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PLOS Global Public Health logoLink to PLOS Global Public Health
. 2024 Mar 28;4(3):e0002986. doi: 10.1371/journal.pgph.0002986

A qualitative inquiry on drivers of COVID-19 vaccine hesitancy among adults in Kenya

Stacey Orangi 1,2,*, Daniel Mbuthia 1, Elwyn Chondo 3, Carol Ngunu 4, Evelyn Kabia 1, John Ojal 5, Edwine Barasa 1,2,6
Editor: Lavanya Vijayasingham7
PMCID: PMC10977730  PMID: 38547132

Abstract

COVID-19 vaccination rates have been low among adults in Kenya (36.7% as of late March 2023) with vaccine hesitancy posing a threat to the COVID-19 vaccination program. This study sought to examine facilitators and barriers to COVID-19 vaccinations in Kenya. We conducted a qualitative cross-sectional study in two purposively selected counties in Kenya. We collected data through 8 focus group discussions with 80 community members and 8 in-depth interviews with health care managers and providers. The data was analyzed using a framework approach focusing on determinants of vaccine hesitancy and their influence on psychological constructs. Barriers to COVID-19 vaccine uptake were related to individual characteristics (males, younger age, perceived health status, belief in herbal medicine, and the lack of autonomy in decision making among women ‐ especially in rural settings), contextual influences (lifting of bans, myths, medical mistrust, cultural and religious beliefs), and COVID-19 vaccine related factors (fear of unknown consequences, side-effects, lack of understanding on how vaccines work and rationale for boosters). However, community health volunteers, trusted leaders, mandates, financial and geographic access influenced COVID-19 vaccine uptake. These drivers of hesitancy mainly related to psychological constructs including confidence, complacency, and constraints. Vaccine hesitancy in Kenya is driven by multiple interconnected factors. These factors are likely to inform evidence-based targeted strategies that are built on trust to address vaccine hesitancy. These strategies could include gender responsive immunization programs, appropriate messaging and consistent communication that target fear, safety concerns, misconceptions and information gaps in line with community concerns. There is need to ensure that the strategies are tested in the local setting and incorporate a multisectoral approach including community health volunteers, religious leaders and community leaders.

Introduction

The Coronavirus disease (COVID-19) was first made a public health emergency in January 2020 and has led to more than 770 million confirmed cases and 7 million deaths globally (as of January 2024) [1]. In May 2023, the World Health Organization (WHO) declared that the COVID-19 disease was no longer a public health emergency [2]. However, there still remains the risk of new emerging variants that could result in a surge of cases and deaths [2].

Due to this risk, the importance of COVID-19 vaccines in protecting against serious illness, hospitalizations, and deaths, persists [3]. Kenya launched the rollout of the COVID-19 vaccines in March 2021 through a phased approach, with plans to vaccinate 100% of the adult population by December 2022. However in late March 2023, two years after the vaccine rollout in the country, only 36.7% of all adults had been fully vaccinated against COVID-19 with multi-vaccine types available in the country (including AstraZeneca, Pfizer, Johnson & Johnsons, Moderna, and Sinopharm vaccines) [4]. This low COVID-19 vaccine uptake could in part be attributed to inequities in access that led to delays in availability of COVID-19 vaccines in low-and middle-income countries [5, 6]. Nonetheless efforts were put in place to address these initial supply-side challenges in Kenya including procurement through the COVID-19 Vaccines Global Access Facility (COVAX), the African Union’s African Vaccine Acquisition Task Team mechanism, and bilateral negotiations. Despite these efforts that ramped up vaccine supply, low vaccine uptake persists. This implies that demand side factors such as vaccine hesitancy threatens vaccine uptake, with estimates of more than a third of the Kenyan adult population classified as vaccine hesitant at the onset of vaccine rollout in the country [7].

Historically in Kenya, routine vaccinations have focused on children and adolescents through the Kenya Expanded Program for Immunization, making adult vaccinations a relatively new initiative, further emphasized by the COVID-19 pandemic. For instance, the seasonal influenza vaccine was recommended for introduction in Kenya in 2016 among children 6 to 23 months of age but was not recommended for any other risk group due to the lack of local burden of disease data [8].

Vaccine hesitancy is defined as the delay in acceptance or complete refusal of vaccination despite their availability [9]. Vaccine hesitancy is deemed to be complex, context specific, varies between time and vaccines and ranges on a continuum from overt acceptance to uncertainty, delay and outright refusal [10]. The prevalence of vaccine hesitancy over several decades and the threat it poses in reversing progress made in addressing vaccine preventable diseases has led to it being listed as one of the top 10 threats to global health in 2019 [11, 12]. Further, Kumar et al (2022) highlight that vaccine hesitancy during the pandemic could have been in multiple phases driven by societal reactions to vaccinations. These include 1) vaccination eagerness in the beginning to reduce mortalities, minimize lockdowns and resume normal life, 2) vaccination ignorance on the development process, safety, efficacy and appropriateness to the vaccine, 3) vaccination resistance led by anti-vaxxer movements, 4) vaccination confidence seen when morbidity and mortality due to COVID-19 was predominantly among the unvaccinated, 5) vaccination complacency preventing people from being fully vaccinated, and 6) vaccination apathy due to disinterest in vaccination [13].

Over the years, there have been different theoretical and conceptual frameworks that have been proposed to assess vaccine hesitancy. Initially focusing on childhood immunizations [10, 1416] but increasingly focusing on COVID-19 vaccines [1719]. In 2015, the 3Cs model categorized determinants of vaccine hesitancy across three categories: confidence, complacency, and convenience [10]. Later, the WHO Strategic Advisory Group of Experts on Immunization (SAGE) described vaccine hesitancy determinants matrix across three main categories: contextual influences, individual and group influences, and vaccine/vaccination specific issues [16]. In the recent years, there was the development of the 5C psychological antecedents that went beyond vaccine confidence and the system that delivers it to include confidence, complacency, constraints, calculation and collective responsibility [15]. A study looking into drivers of vaccine hesitancy in childhood vaccines in the African context used a conceptual framework incorporating three drivers of vaccine hesitancy i.e. caregiver-related factors, health systems related factors and community context [14, 15]. The framework assumed that these factors make individuals hesitant by influencing one or more of the 5C psychological constructs [14, 15]. The health belief model has also been used as a guide to explore factors influencing health beliefs regarding vaccine hesitancy [17, 18].

Globally, COVID-19 vaccine hesitancy across different demographic and cultural contexts has been reported to be influenced by risk perceptions, previous experiences with vaccines, trust in health care systems, misinformation, concerns about side effects and political ideology [20]. Further, low-income and middle-income countries report vaccine hesitancy among 20% of adults with safety and efficacy concerns being the most cited reason for hesitancy [21]. Previous evidence in Kenya highlight COVID-19 vaccine hesitancy as a challenge with almost all the studies using quantitative methods to determine drivers of vaccine hesitancy [7, 2230]. Some of the studies focus on sub-groups of the Kenyan population including refugees, [27, 29] pregnant and lactating women, [23, 31] community health volunteers [24] and the youth [25]. Despite this, ongoing research into vaccine hesitancy is needed to understand the attitudes, beliefs and decisions around adult vaccination, in general, as this may have an impact on preparedness for future pandemics and future routine vaccines rolled out to adults such as the seasonal influenza vaccine. Specifically, there is need for more qualitative studies for in-depth exploration of drivers that influence people to be vaccinated or not, which might be helpful in shaping the future strategies of adult vaccination in the Kenyan context.

In this study, we explore participants’ decisions around whether or not to receive the COVID-19 vaccine and the reasons behind them. By doing so, we are contributing to the understanding of facilitators and barriers to adult vaccinations in the Kenyan context.

Methods

Conceptual framework

We adapted a conceptual framework to assess the different determinants of vaccine hesitancy as derived largely from scoping reviews of literature on drivers of COVID-19 vaccine uptake [18, 19]. Moreover, given the cross-cutting themes with frameworks from childhood immunizations, we also incorporated relevant determinants from literature focussed on childhood immunization [10, 1416]. Determinants of vaccine hesitancy were broadly classified across 4 sub-groups based on WHO SAGE framework [16]. Further, appropriate drivers of vaccine hesitancy identified from other frameworks were also classified into the 4 sub-groups [14, 1719]. First, individual perceptions which explored how socio-demographic factors and individual perceptions such as past experiences with other vaccinations, trust in herbal medicine, conspiracy beliefs, perceived general health, altruism and collectivism influence vaccine hesitancy. Second, contextual and social influences, such as the communication and media environment, vaccine recommendations, trust in health systems/providers/government, religion/culture, and geographic barriers, and their influence on vaccine hesitancy. Third, COVID-19 vaccine and related factors including attitudes and beliefs, vaccine benefits/vaccine risks, knowledge and awareness on vaccination, length of development and clinical testing, and the type of vaccine. Lastly, COVID-19 infection and related factors such as perceived susceptibility and severity to COVID-19 (for self and others), and knowledge, attitudes, and practices regarding COVID-19 infection and their influence on vaccine hesitancy.

Given the criticism that vaccine hesitancy has previously neglected psychological states in its definition [32, 33], our conceptual framework also sought to analyse the influence of the aforementioned determinants of vaccine hesitancy on one-or more of the 5C psychological constructs: confidence, complacency, constraints, calculation, and collective responsibility [15]. Confidence refers to the trust in safety and effectiveness of the vaccine, the system that delivers it and the motivation of the leaders who decide on the need for vaccines [15]. Complacency exists when vaccination is not deemed necessary and there is a low perceived risk of the disease [15]. Constraints refers to structural and psychological barriers while, calculation refers to a person’s engagement in information searching [15]. Lastly, collective responsibility is the willingness to protect others through herd immunity by being vaccinated [15].

In our conceptual framework, the four determinants of vaccine hesitancy interact, and influence one or more of the psychological constructs which in turn determine an individual’s decision on vaccination. The individual decision about vaccination lies across a spectrum from complete refusal to complete acceptance of the vaccine and may vary across time. Decisions on COVID-19 vaccination that are either complete refusal, refusal but not certain (initially refuses and may delay in getting vaccinated), or acceptance but not certain (although accepted to be vaccinated, are uncertain about their decision) comprises vaccine hesitancy. This is illustrated in Fig 1.

Fig 1. Conceptual framework on drivers of vaccine hesitancy.

Fig 1

The limitation of using a conceptual framework in data analysis is that the themes identified may be limited to those in line with the framework. However, to mitigate this, any new emerging themes outside of the conceptual framework were identified during analysis.

Study setting

This study was conducted in two counties in Kenya, Nairobi and Kilifi. These counties were purposively selected to represent urban (Nairobi) and rural (Kilifi) settings, different geographic regions, and a high (Nairobi) versus low (Kilifi) COVID-19 vaccination coverage. This was done so as to identify any differences that may exist in the different settings. As of 22nd March 2023, Nairobi and Kilifi reported 57.1% and 21.3% of fully vaccinated adults respectively against the national average of 37.6% [4].

Focus group discussions (FGDs) and in-depth interviews (IDIs) were conducted in two sub-counties in Kilifi (Kilifi North and Malindi sub-counties) and Nairobi (Dagoretti and Makadara sub-counties). The sub-counties were purposively selected in consultation with county managers, to represent sub-counties with high and low vaccine coverage.

Study design and data collection

We conducted a cross-sectional qualitative study design using 8 FGDs with 10 participants each and 8 IDIs with health care workers and county managers. FGDs were deemed an appropriate method to gain in-depth shared knowledge from community members on vaccine hesitancy. While IDIs were preferred to elicit individual views from health care workers on community member’ vaccine hesitancy.

In each sub-county, two FGDs were done with the elderly (50 years and above) and those of a younger age (18–49 years). One or two community health volunteer(s) (CHV) were identified in each of the sub-counties. The CHVs assisted in purposive sampling and contacting eligible FGD participants from the community based on pre-specified varied characteristics such as socio-demographic parameters (age, gender, socio-economic, and education status) and COVID-19 vaccination status (a mix of those who were vaccinated, unvaccinated, and partially vaccinated). CHVs were deemed appropriate to contact FGD participants given their ability to easily identify community members based on the pre-specified criteria and their credibility in the community.

The participants were invited to a community hall where they had an initial information session to provide further information on the study and provide informed consent. The information session held by the researchers prior to the FGDs served to help mitigate the risk of undue influence that participants may have, through using CHVs in selecting potential participants. FGDs were then conducted face-to-face in community halls for an average duration of 60 to 90 minutes. FGDs were conducted in Swahili, the language mainly used by community members in Nairobi and Kilifi. To supplement the FGDs, IDIs were conducted with health care workers and county managers involved in community demand generation activities of the COVID-19 vaccine. These IDI participants were purposively sampled and included 4 nurses, 1 community health assistant (identified from selected health centres and hospitals) and 3 county health managers involved in immunization activities. FGDs and IDIs were audio-recorded with the participants’ consent and augmented by field notes. IDIs were conducted using semi-structured interview guides while discussion guides were used to moderate the FGDs. Questions in the interview and discussion guides were developed based on the study’s conceptual framework (Fig 1) which assessed different determinants of vaccine hesitancy.

Debrief sessions during data collection were held between the two authors (SO, DM) to improve the interviewing process and aid with the revision of some questions in the interview/discussion guide for better clarity and to include emerging themes that needed to be explored further. Data collection was discontinued when data saturation was achieved. Data was collected from participants between 11 October 2022 and 14 December 2022.

Participants

The FGDs participants comprised of both men (39 participants) and women (41 participants). The median age of the participants was 47.5 years with an age range of 18 years to 81 years. A majority of the participants were married (54%, n = 43), had a secondary school education (49%, n = 39), were unemployed (49%, n = 39), and were of Christian faith (88%, n = 70). Most of the FGD participants were vaccinated (80%, n = 64), with at least one dose and of those only about half (34 participants) had received the booster dose. 8 IDIs were conducted with health care workers involved in demand generation activities. Table 1 provides more details on the distribution of FGD participants in the study counties by socio-demographic characteristics.

Table 1. FGD participant characteristics.

Kilifi County Nairobi County Summary of FGD participants
FGD 1 FGD 2 FGD 3 FGD 4 Total FGD 5 FGD 6 FGD 7 FGD 8 Total
Sex
Male 5 5 3 7 20 5 4 5 5 19 39
Female 5 5 7 3 20 5 6 5 5 20 41
Age
Median age 26 66.5 56.5 31 49.5 30 67 28 63 46.5 47.5
Age range 18–44 50–79 50–73 19–49 18–79 19–47 45–81 19–48 50–74 19–81 18–81
Marital status
Married 4 6 5 5 20 6 6 4 7 23 43
Divorced/Separated 1 1 2 1 5 0 1 0 0 1 6
Widowed 0 2 2 0 4 1 3 0 0 4 8
Single 5 0 1 4 10 3 0 6 3 12 22
Education
No education 0 2 0 0 2 0 2 0 0 2 4
Primary school 2 4 2 2 10 1 4 0 6 11 21
Secondary school 5 4 7 5 21 6 3 7 2 18 39
Tertiary school 3 0 1 3 7 3 1 3 2 9 16
Employment
Full-time employment 1 2 0 0 3 1 1 1 1 4 7
Part-time employment 2 0 3 3 8 1 0 1 3 5 13
Self-employed 1 3 1 2 7 2 4 0 2 8 15
Student 2 0 0 1 3 2 0 1 0 3 6
Unemployed 4 5 6 4 19 4 5 7 4 20 39
Religion
Christian 8 7 7 8 30 10 10 10 10 40 70
Muslim 2 3 3 2 10 0 0 0 0 0 10
COVID-19 vaccination
Vaccinated 8 9 10 9 36 5 9 9 5 28 64
Unvaccinated 2 1 0 1 4 5 1 1 5 12 16
Booster dose .
Received booster 4 3 5 6 18 4 6 3 3 16 34
Not received booster 6 7 5 4 22 6 4 7 7 24 46

Data analysis

First, audio recordings were translated verbatim, those in Swahili were then translated to English. The data was then analysed using a framework approach that entailed familiarization, coding, charting, and interpreting the results [34]. We familiarized ourselves with the data by listening to the audios and re-reading the transcripts and field notes. The transcripts were then imported to NVIVO 12 (QSR International) for coding based on the determinants of vaccine hesitancy. Further, we mapped the influence (positive/negative) of the determinants on any of the psychological constructs and their influence on vaccine hesitancy illustrated through a causal loop diagram. In the casual loop diagram, how the variables influence each other is illustrated using an arrow. A feedback loop is shown when factors interconnect with each other. A balancing (B) feedback loop refers to the counter effect by the interconnected variables while a reinforcing (R) feedback loop refers to more of the effect being generated. After line-by-line coding and indexing all transcripts based on codes and themes, while ensuring all new emerging themes were captured, we charted the data. Charting the data into framework matrices was done by summarizing the themes and identifying illustrative quotes. Lastly, interpretation of the data was done by identifying connections between the various themes and gaining a better understanding on community members drivers of COVID-19 vaccine hesitancy.

Ethical considerations

Ethical approval for the study was obtained from the Kenya Medical Research Institute Scientific and Ethics Review Unit (KEMRI/SERU/CGMR-C 4244). Written informed consent was obtained from the participants prior to data collection. Participants were made aware that their participation was voluntary and that confidentiality in the research would be maintained.

Results

The results are presented based on the four determinants of vaccine hesitancy: individual perceptions, contextual/social influences, COVID-19 vaccine & related factors, and COVID-19 infection and related factors. We also present how these determinants relate to any of the psychological constructs. Brief summaries of the key findings are provided under each determinant.

Individual perceptions

Differences in socio-demographic characteristics were drivers of vaccine hesitancy

Study respondents reported that those of a younger age were more hesitant to receive the COVID-19 vaccine. This is because they had a perception of not being at risk of COVID-19.

“Somebody is thinking they are currently healthy; maybe they are the ones who can go and work. Most people say, “I am the breadwinner (but) you want to vaccinate me so that I’ll be in bed (due to side-effects)? Who’s going to look after my family?” Nursing officer 3, rural county

Men compared to women reported to have poor health seeking behaviours and competing work priorities that made them more hesitant to receive the vaccine. Further, the men perceived that the COVID-19 vaccine had a side effect that affected their sexual health, and this deterred them from vaccination.

“Men refuse more than women. They refuse because they have a problem with going to hospital even if it is because of other diseases, other than corona …By the time they are going to hospital the disease has spread and it’s out of hand.” FGD 6, urban county [over 50years]

Men were the ones who had more issues and the youth from the rumours that they would become impotent from the vaccines. Up to date, a lot of them still hold to that belief. " FGD7, urban county [18-49years]

In the rural areas, a majority of women lacked autonomy in deciding whether they should be vaccinated. This responsibility lies with their husbands or partners. However, this did not apply in the urban setting.

“In most homes, women do not have the power to make decisions unless their husbands make them. Even for the children, from the mother to the children. The man has to talk for us (women) to accept. Until the man talks, they cannot agree to it. This is because he is the house head, he has to know about it. This is because if you give a vaccine to the wife and she gets side effects, it will be like the man failed in protecting the wife.” FGD 3, rural county [18–49 years]

“I can say there is freedom of choice to get vaccinated for both men and women, because no one was really asking the other if they should go get it, you just decide on your own and go.” FGD 5, urban county [18-49years]

There were beliefs in traditional or herbal remedies as alternatives to COVID-19 vaccination

In both the urban and rural settings, respondents cited community members having beliefs in herbal medicines to prevent or treat COVID-19. In some cases, these remedies were deemed sufficient and the need for vaccination was not perceived.

“People in the interior areas have made their own drugs to prevent them from getting COVID. They can tell you to take lemon, ginger and blend them together and consume and it will be over. These lemons were not even available in the market …The people from tribe X also have their beliefs, (some) do not believe in the hospitals. They believe in taking herbal medicine.” FGD 4, rural county [over 50 years]

“There was also another person saying that if you go to the market and buy lemon, boil water and put it with garlic, COVID will be so far from you, so we saw that there’s no need of being vaccinated if you can treat yourself.” FGD 8, urban county [over 50 years]

In some cases, health status and past experiences with vaccination were drivers of vaccine hesitancy

While a majority of respondents reported that having comorbidities was a risk factor for COVID-19 infection, some respondents expressed concerns about being vaccinated while having comorbidities. Moreover, pregnant and lactating mothers were concerned about the safety of COVID-19 vaccines on the foetus and perceived that vaccination would cause reduced breast milk.

“We were instilled fear. I have diabetes, high blood pressure and other conditions and we were made to fear that if a diabetic and hypertensive person goes to be injected they can die …I’ve not been injected because I have high blood pressure and feared.” FGD 6, urban county [over 50years]

“Initially they (pregnant and lactating mothers) did not accept to it … I got my first dose when I was five months pregnant. There is another person who went for it after she saw that I have gotten it …They used to say that when you get it, the baby will die before being born or he will be disabled. Right now, people are enlightened, even those who are breastfeeding are getting it. Initially they used to say that when you get it when you are breastfeeding, you will not have enough milk to give your child.” FGD 3, rural county [18-49years]

Respondents past experiences with other vaccines (e.g. childhood vaccines) or other medicines administered through injections, influenced their uptake of COVID-19 vaccine. For example, respondents who had a fear of needles, were more likely to be hesitant to receive the COVID-19 vaccine.

“I’ve been fearing vaccines since birth, not just COVID but any injection. I prefer being vaccinated in the ward so that I can’t run away, so I just feared. I have not even been injected (COVID-19 vaccine), even one.” FGD 8, urban county [over 50 years]

“There are other people who don’t like injections. They are scared.” FGD 1, rural county [18–49 years]

Contextual influences

Structural differences in employment were a driver of vaccine hesitancy

Respondents on a daily wage were reported to be more hesitant to receive the COVID-19 vaccine due to time constraints and the possibility of missing work due to side effects. This was unlike those in employment who have some protections such as paid sick leave.

“We work on hand to mouth basis: you use up everything that you’ve made that day so I cannot get the time to go and get vaccinated.” FGD 1, rural county [18-49years]

There were several reported media and communication channels which influenced perceptions of vaccines and as a result vaccine hesitancy/uptake to different extents

Respondents reported having heard about COVID-19 vaccination from different sources including international organizations like the World Health Organization, work, village leaders, media, health care workers, government and religious institutions. Although social media did play a role in vaccine uptake, it was also one of the greatest sources of promoting vaccine hesitancy.

“Others got the information on COVID-19 from social media channels. When you enquire much about the information, you will find that some had exaggerated a lot. So, you will find that they have talked more of the negatives than the positives of COVID 19 vaccine. You will find young people or even people in the community are resisting because of what they have seen online.” FGD 3, rural county [18-49years]

“Again, social media: Facebook and Twitter, there was writing of negative stuff in relation to COVID vaccines. As you are trying to convince someone (to be vaccinated), they show you from their phones what is going on, and you see this thing (social media) has a large audience, so, they conclude this thing (COVID vaccine) is not good for human consumption.” FGD 7, urban county [18-49years]

On the other hand, COVID-19 vaccines were taken up mostly due to information provided by CHVs. This is because CHVs are known and trusted by the community.

“At first people did not believe that there is COVID, so through the CHVs and since they are close to the community many of us trust them …you find even there are other vaccines that people don’t want to give their children but through the CHVs they trust them that there is no day they’re going to introduce them to anything harmful.” FGD 1, rural county [18-49years]

“Here we do have CHVs, they were going around announcing and then later they set up vaccination stations. We believed them and went to get vaccinated…The CHVs, they are advising people and assuring those who are afraid. Like myself I was afraid but the CHV came and reassured me, and I got the vaccine.” FGD 5, urban county [18-49years]

Leaders were influential in promoting vaccine uptake and in some cases driving hesitancy

Political and religious leaders either recommending the vaccine or taking the vaccine publicly was a key driver in vaccine uptake. However, some respondents reported a lack of trust in the government which was a driver of vaccine hesitancy.

“We believed when we saw our president getting vaccinated. When I saw bishops who were above me being vaccinated, I saw it is for all and joined. " FGD 8, urban county [over 50years]

“They also believe that the government is in business. When you go to people they will tell you that corona is over and the government is now doing business so as to get funding…Yes, they do not trust the government, what they say is not what they do.” FGD 4, rural county [over 50years]

There were cultural and religious beliefs that deterred vaccine uptake among community members

In the rural setting, there were beliefs that a similar disease to COVID-19 existed in the past and was cured through the use of traditional medicine. Therefore, during the pandemic, the use of vaccines was not recognized.

“There were others who were saying that this disease they are being told about now has been there since long time back. The people from tribe X called it ‘kivuti’. Kivuti had its own medicine which people long time ago could take when they were sick …They were taking traditional medicines. They were questioning whether it is now that the others have learnt about the disease which has been there. They made traditional medicines which they believed treated them.” FGD 4, rural county [over 50 years]

“When there was a ‘kivuti’ outbreak (in the past), traditional medicines were prepared, someone is given, and people are made to stay far from him. With time he would heal. Earlier on they had not discovered the medicine but later on they came to discover different trees which could be boiled and become a cure to the disease.” FGD 2, rural county [over 50 years]

Others reported having religious beliefs that made them hesitant to receive the vaccine.

“There are those who do not believe in anything to do with medicine. When they get sick, they just kneel down and pray to God to heal them. If God does not heal them, then they are ready to die. There are many people who believe in that here.” FGD 4, rural county [over 50years]

“For me, my mum told me to believe in God, same way He has kept me from those other diseases He will protect me from Corona too. So, for me, I just believe in God’s protection over this.” FGD 5, urban county [18-49years]

Non-pharmaceutical restrictions, movement restrictions, and other access restrictions that were enforced, promoted vaccine uptake

Early on in the pandemic, there was enforcement of travel, work, and other access restrictions. These influenced some community members who were initially hesitant, to accept the COVID-19 vaccination.

“I got it because the minister of health said you can’t go to Mombasa if you have not been vaccinated so I just had to get vaccinated …Then also, there are those who want to travel to other countries so you find if you are not vaccinated you cannot cross the border or accepted in another country so that has an effect.” FGD 1, rural county[18-49years]

“It was said that if someone is not vaccinated the person will not travel using a matatu, won’t be paid, won’t work, you see? So, I saw that my years (worked) will get lost. The years that I’ve served at work are many years, will they get lost because of three injections? I saw that I’d rather agree …if it were not for the rule that said no service will continue if you are not vaccinated, I would not have come.” FGD 8, urban county [over 50years]

However, removal of the travel restrictions, access restrictions, and other non-pharmaceutical interventions, coupled with the shifting government priorities created a perception that COVID-19 is no longer in existence or a threat hence there was no need for vaccination.

“There are others who thought that since they have been told not to put on masks, there is no more corona. This affects people getting the vaccine.” FGD 2, rural county [over 50years]

“Removal of the COVID measures is what caused the decline (in vaccination), everyone now thinks corona is gone …right now even if one received the second one or the booster, they don’t see the need to go back, because it seems corona is gone …So, people were of the perception that now that the government has relaxed the measures it means the disease is gone.” FGD 5, urban county [18-49years]

Geographic and financial barriers to access COVID-19 vaccines were addressed

Initially, vaccination was only offered in health care facilities, resulting in long waiting times. However, the respondents reported that when the vaccination strategy evolved to a mixed approach including outreaches and mass campaigns, acceptance of COVID-19 vaccines increased. Transport costs and waiting times were no longer a barrier to access the vaccines. Highlighting ease of access being a driver of vaccine uptake.

“You can get the vaccine anywhere, sometimes they go out for outreaches, door to door, sometimes schools, dispensary, churches, mosques … it has been good going to vaccinate people where they are, because most of them do not go to the dispensary to get these vaccines. When you take the vaccine next to them, when they see that others are getting them, they also get. Others wonder whether they have to go long distances, they request for the services to be brought near them. " FGD 3, rural county [18-49years]

“For me I didn’t even go to look for that booster, it came to where I stay and I got injected. I see them coming there sometimes and when people hear that the injection is there as they pass, they go, get injected and continue with their journey.” FGD 6, urban county [over 50years]

There were wide-spread rumours and myths that drove vaccine hesitancy

Due to the novelty of the vaccine and novelty of vaccinating adults in Kenya, respondents reported having beliefs in several rumours and myths regarding COVID-19 vaccines. These included rumours that the vaccine would cause infertility, deaths among those vaccinated, and was being used as a tool to track and monitor people.

“Many of them think it came to control the population. Now if you go to the community and ask “have you been vaccinated?” they say “wait for 10 years you’re going to die”. Others say you’re going to turn into a zombie. Others say it’s a form of tracking. Others are saying the population in Kenya is being reduced.” FGD 1, rural county [18-49years]

“ Even when the injection first came it was said that it belongs to people who are 58 and above so others said that they want to eradicate the elderly.” FGD 6, urban county [over 50years]

Despite these rumours, there were efforts to dispel the rumours through education and sensitization by the CHVs.

“When COVID came around all CHVs were called, to get some training on what to teach the community. And from the information they had, they tried to give them the right information as opposed to the rumours.” FGD 7, urban county [18-49years]

COVID-19 vaccine and related factors

Although benefits of vaccination were recognized, the concerns on vaccine safety drove hesitancy

Respondents cited the primary benefit of the COVID-19 vaccine as protection of self and others from COVID-19 infection and death. Other perceived benefits of vaccination by respondents included being able to work and travel without the risk of infection. However, as a result of the side effects that people were experiencing, there were concerns on the safety of the vaccine. These side effects included pain on the injection site, fever, body aches, flu-like symptoms, among others.

“On my part I have not been vaccinated. My husband was among the first to get the vaccine and when he came back after the vaccine, he really got sick … It took him like two weeks, being indoors sick and not going to work. He later on recovered. After some time, he went for the second jab, and still became sick … So, I have never been vaccinated, due to that scare.” FGD 5, urban county [18-49years]

“People were scared of the second dose or the booster because of the side effects they got. The booster really made me sick … Like for 2 weeks, it really made me sick.” FGD 1, rural county [18-49years]

The short time taken to develop the vaccine was also a major concern to many respondents and raised questions on vaccine safety.

“It was made very fast. They were saying that for a vaccine to be made, it needs to have been researched on for like ten years, but for this one that they have gotten within one year, they (community members) think that it is not safe.” FGD 4, rural county [over 50years]

“We were more worried because we were telling each other that for HIV, (the vaccine) is yet to come around for all those years, how come the COVID-19 one got discovered that fast and COVID-19 kills people just like AIDS.” FGD 7, urban county [18-49years]

Respondents were also concerned about the unknown long-term side effects of the COVID-19 vaccine.

“You know they have told us the immediate side-effects; we don’t know about long term effects, if it is going to have long term effects or not. They should explain to us clearly the long-term effects rather than just the short-term effects. Maybe some organs might be affected, or other things might happen, so they need to be honest with us.” FGD 1, rural county [18-49years]

“Fear of the unknown. A person can say that he does not know when he gets the vaccine, if he will get sicker.” Nursing officer 2, rural county

There was a lack of knowledge and misinformation on vaccines which drove hesitancy

There was misinformation among the respondents on how vaccines work in general. This coupled with a lack of understanding on the need for boosters, number of booster doses to be given, and the mixing of vaccine types, was a driver of COVID-19 vaccine hesitancy.

“There are some who are told that you can get the virus from the vaccine, so the person sees it as if you’re taking yourself to get COVID-19 …Others were saying, when they get sick, is when they’ll be vaccinated, so, that when the vaccine goes in, it can fight off with the disease. They were adamant, they can’t be vaccinated, and they are not sick, or in pain whatsoever.” FGD 7, urban county [18-49years]

“People wonder that they have gotten a first dose from Moderna, Pfizer or Astra Zeneca, what is the need of a booster if the vaccine is good? Some will even question the booster, why get a second booster? It is a challenge with those number of jabs. People are not comfortable with it. " FGD 3, rural county [18-49years]

The availability of different vaccine types influenced vaccine acceptability

There were vaccine preferences among the respondents that were largely based on the number of injections and experienced side effects.

“Maybe someone saw somebody get AstraZeneca and got serious side effects when they come get vaccinated they say they don’t want that…The government should make sure all the vaccines are available if someone comes and wants a certain vaccination it should be available. Someone may not get the vaccination they want and get demoralized.” FGD 1, rural county [18-49years]

“Most people wanted that Johnson because it is one dose and you won’t be pushed so much. You get injected once and won’t go back to that injection again. Most people really wanted that one.” FGD 6, urban county [over 50 years]

Further, vaccine stockouts throughout the country of some of the vaccine types, influenced by supply-side challenges may be a driver of vaccine hesitancy. Especially to special populations groups that are eligible to receive certain vaccine types (e.g. pregnant women were eligible to receive mRNA vaccines) or those with specific vaccine preferences.

“It (vaccine stockouts) affects me in a big way, especially, Pfizer. Pfizer is meant for pregnant mothers, lactating mothers, and children between 12 and 17. For instance, the last two months, Pfizer was out of stock in the whole country, so, we were not able to vaccinate those people, they were coming here, and we have to send them away. So, that’s the biggest challenge when it comes to supply. I have these target populations I need to immunize, and I can’t do it.” Nursing officer 4, urban county

There were attitudes and beliefs around COVID-19 vaccination that drove hesitancy

Respondents cited concerns on mixing vaccine brands and this would result in missing the second vaccine dose or not taking booster shots.

“In the beginning when you were vaccinated with AstraZeneca you were to only be given AstraZeneca. For now it is not there. People wonder if they mix up the vaccines, it may affect them.” FGD 1, rural county [18-49years]

“Another thing is that we fear the booster … Then you are told for the booster that you will not necessarily get the vaccine type that you got initially. You could get a different one. I am afraid of that up to now.” FGD 2, rural county [over 50years]

The novelty of adult vaccination in comparison to childhood vaccination was recognized as being a potential driver of vaccine hesitancy. Further, community members had adequate sensitization on the importance of childhood vaccines, unlike adult vaccines.

“In my opinion all this is brought about because we are the first ones to use the COVID-19 vaccination but our next generation they are going to receive it well but you know when you’re the first one to start something it is hard. The beginning of something is usually hard. That is why we have these challenges … So maybe even when polio began it was hard for their parents.” FGD 1 rural county [18-49years]

“Children vaccination is very serious. Even when you don’t have fare and you don’t take them the father is going to quarrel you, "the child had a vaccination why didn’t you go?" but now adult vaccination…" FGD 1, rural county [18-49years]

COVID-19 infection and related factors

Perceived susceptibility and likelihood of developing severe COVID-19 for self and others contributed to hesitancy

A majority of the respondents perceived the elderly and those with co-morbidities to be the most susceptible to COVID-19 and therefore more likely to be vaccinated. The young had a lot of negative peer influence and perceived themselves to be of good health, hence driving hesitancy.

“You know adolescents they are in groups. So, if one of them says they are not getting vaccinated the others will also follow. They say they’re not going to get vaccinated. The old people are the ones to get COVID-19. So, it makes them say they have no need for that vaccination because they see they have a strong immunity and they’re still young.” FGD 1, rural county [18-49years]

Influence on psychological constructs

The causal loop diagram (Fig 2) illustrates the linkage between the drivers of vaccine hesitancy, and how they are interrelated with the psychological constructs and vaccine hesitancy. The main psychological antecedents to vaccination were identified as confidence, constraints and complacency in this study setting.

Fig 2. Causal loop diagram of drivers and psychological constructs of COVID-19 vaccine hesitancy in Kenya.

Fig 2

The relationship between the three psychological constructs and vaccine hesitancy have reinforcing feedback loops as illustrated in the causal loop diagram. Therefore, when individuals have low confidence in the COVID-19 vaccine, are highly complacent, and there are high number of constraints in the system, this leads to increased vaccine hesitancy. Conversely, when vaccine hesitancy is high, individual’s overall confidence in the vaccine is low, they would be more complacent, and there may be no motivation to address the constraints in the system.

Discussion

This study reports qualitative findings on drivers of vaccine hesitancy and how they relate to psychological constructs among adults in Kenya, almost 2 years after vaccine rollout. This study suggests that drivers of vaccine hesitancy in Kenya, as in other settings are complex [20, 21], interrelated and a lack of confidence, high complacency and constraints are critical factors to consider for increased vaccine uptake.

In relation to individual characteristics, our study highlights that the youth were more complacent to receive the COVID-19 vaccine. This is because they report having a good health status and are more likely to interact with negative information on social media regarding the COVID-19 vaccine. Additionally, a lack of autonomy in decision making among women and children in rural settings was a constraint leading to vaccine hesitancy. This points out the need for gender-responsive immunization programs that could include tailored community engagements with men, women, and the youth in the design of immunization delivery and implementation strategies while addressing their concerns [35]. Evidence from Kenya, highlights the need for more evidence-based engagements with the youth to increase uptake [25].

Several contextual factors were highlighted as drivers of vaccine hesitancy. First, the medium of communicating messages to promote COVID-19 vaccination is important in influencing vaccine confidence. There is consistent evidence from other studies in similar settings such as Cameroon, Ivory Coast and Nigeria that report social media platforms as a channel for inaccurate data on COVID-19 vaccines [3638]. Social media’s algorithm is tailored to compound exposure and reflect previous searches: Therefore if a person searches for and consumes information on vaccine hesitancy, they are more likely to be exposed to such content in future [39]. Further, there may be difficulty in a lay person determining credibility of the information [39]. Interestingly, experimental studies have demonstrated that viewing anti-vaccination content on social media increased negative beliefs on vaccination but viewing pro-vaccination content had minimal effects on beliefs [40, 41]. This highlights the need to identify the misinformation techniques used on social media (including conspiracies, fake experts, skewing the science, shifting hypotheses, censorship, misrepresentation and false logic), disentangle the core points and respond with evidence-based messages [4244]. Further, there could be collaborations with technoloogy platforms to spread accurate information that leverages on community-driven concerns.

In line with the findings of this study, CHVs who are trusted and perceived as influential should continuously be engaged, trained and incentivized to disseminate the evidence-based messages. This would also be instrumental in building health systems preparedness and resilience in future crises. Myths and rumours from this study that are likely to emerge during other pandemics such as population control, long term negative effects can be used to inform preparedness for any future epidemics or pandemics.

Second, we report that religious and cultural beliefs also influence vaccine confidence and inform vaccine hesitancy. Similarly, a large majority from Niger, Liberia and Senegal report prayer as more effective in protection against COVID-19 compared to vaccination [45]. This emphasises the need for a multisectoral approach beyond the health sector and among various stakeholder groups. This deliberate collaboration and engagement of multiple sectors (such as with religious, cultural leaders, civil society) would leverage on diverse expertise, knowledge, reach and resources towards building trust in vaccines [46].

Third, lifting of restrictions and vaccination mandates led to individuals being complacent to vaccination. Our findings suggest that the enforcement of vaccination mandates for employment and travel compelled some community members who were hesitant to accept vaccination, because they valued their freedom to move and work. Further, upon removal of vaccination mandates, there was a perception that COVID-19 was no longer a risk, influencing vaccine uptake. There is evidence to suggest that COVID-19 vaccination mandates were associated with a rapid and significance rise in vaccinations in Canada and parts of Europe [47]. In Zimbabwe, there is report of high acceptance for COVID-19 vaccination mandates, which were strongly associated with perceptions of vaccine safety, effectiveness, and trust in the regulatory process [48]. On the contrary, vaccine mandates have also been reported to have unintended consequences including widening societal inequities, impacting on trust in governments, and reducing uptake of future public health measures [49, 50]. Further, vaccine mandates can impact on individual agency, a failure to fully address the root of vaccine hesitancy.

More sustainable approaches can be implemented that are built on trust and public debate to help the community to better understand the risk and benefits of the vaccine [49]. On the other hand, national mandates that allow for time away from work for vaccination during pandemics or work based vaccination programs could be considered to address productivity concerns and timings that were drivers to vaccine hesitancy.

COVID-19 vaccine safety concerns either because of the side effects experienced, the fear of unknown long-term side effects or the short time taken to develop the vaccine influenced respondents confidence in vaccination. Similarly, other evidence from Africa, South Asia, and Europe have highlighted concerns of vaccine safety, side effects and efficacy as one of the main concerns driving vaccine hesitancy [5153]. While some experimental studies have shown the effect of different messaging for COVID-19 on vaccine intentions [54, 55], others report no effect on vaccine hesitancy by providing messages about vaccine risks and the development process to respondents [56]. This highlights the complexity in tailoring appropriate messaging, with appropriate frequency and delivery, especially in settings with slow vaccination coverage and a large vaccine hesitant population. Targeted messaging should be accompanied with message testing in the specific context as evidence suggests that messaging aimed at stimulating rational thinking of vaccine safety may in some cases not only be ineffective at positive change but could be counterproductive [57, 58]. Perhaps equally important, in addition to addressing COVID-19 vaccine safety concerns, our study highlights the need to provide a broader understanding on how vaccines work in general and the rationale for booster doses among the population, which would be beneficial in sensitisation to even other adult vaccines in the Kenyan context.

Our findings point out that vaccine hesitancy varies across time. Time-dimension coupled with exposure to new information and seeing others with positive experiences is a driver that can address hesitancy. This highlights the importance of consistent awareness building and right messaging over time.

In this study, we hypothesize reinforcing feedback loops between the three psychological constructs (confidence, complacency, and constraints) and vaccine hesitancy. Implying that when vaccine hesitancy is high, vaccine confidence is low, individuals are complacent and there are no motivations to address constrains in the system. On the other hand, when individuals have low confidence in the vaccine, are highly complacent and there are many constraints in the system, there is increased vaccine hesitancy. These feedback loops highlight the potential undesirable cycles that can consequently affect coverage level. Similar findings of reinforcing feedback loops between confidence and constraints with vaccine hesitancy are reported in a study from African settings on childhood vaccines [14].

We recommend further work on the relationship between the psychological constructs and determinants of hesitancy, especially for adult vaccines. There is also a need for future in-depth analysis on reasons why awareness campaigns in the local context may not have managed to dispel rumours and fears on the vaccine, as well as how traditional remedies are perceived.

The strength of this study is that it highlights the facilitators and barriers of COVID-19 vaccine hesitancy among community members (including both young adults and the elderly) in a rural and urban setting of Kenya. However, the study has some limitations. First, the findings of this study may not be generalizable, outside of these selected Kenyan counties. Second, due to the cross-sectional nature of the study and the fact that vaccine hesitancy varies across time, we were unable to account for temporal variations. Third, there may have been a social desirability bias among the participants to respond in a manner that is viewed favourable by others. This could have influenced how they self-reported their vaccination status or their narratives on vaccine hesitancy. Fourth, there was a lower participant consent rate among those unvaccinated at the time of the study.

This study aligns with initiatives promoting vaccine equity because beyond addressing inequitable vaccine distribution, overcoming vaccine hesitancy is necessary to achieve vaccine equity [59]. While COVID-19 is no longer a public health emergency, this study contributes to the knowledge of drivers of vaccine hesitancy in the local context that can inform preparedness of future pandemics and future routine vaccines rolled out to adults such as the seasonal influenza vaccine.

Conclusions

COVID-19 vaccine hesitancy in Kenya is driven by multiple interconnected factors related to individual perceptions, contextual influences and COVID-19 vaccine and disease related concerns. These factors are likely to inform evidence-based targeted strategies that are built on trust to address vaccine hesitancy. These strategies could include gender responsive immunization programs, appropriate messaging and consistent communication that target fear, safety concerns, misconceptions and information gaps in line with community concerns. There is need to ensure that the strategies are tested in the local setting and incorporate a multisectoral approach including community health volunteers, community and religious leaders.

Data Availability

The data presented in this study are available upon reasonable request from the corresponding author through the email dgc@kemri-wellcome.org. Public deposition of the transcripts would breach compliance with the approved protocol. During ethical approval, the transcripts were stated would be available publicly upon reasonable request through KEMRI-Wellcome Trust’s data governance committee through the email dgc@kemri-wellcome.org. This was because at the time of data collection, it was deemed a sensitive topic, it was paramount not to compromise patient privacy, and allow free participation among the respondents. We are therefore kindly requesting for this exemption.

Funding Statement

This work was supported by funding from the International Decision Support Initiative (IDSI) (EB, SO). Additional funds from a Wellcome Trust core grant awarded to the KEMRI-Wellcome Trust Research Program (#092654) (EB) and the German Academic Exchange Service (DAAD) (SO). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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PLOS Glob Public Health. doi: 10.1371/journal.pgph.0002986.r001

Decision Letter 0

Lavanya Vijayasingham

7 Nov 2023

PGPH-D-23-02085

A qualitative inquiry on drivers of COVID-19 vaccine hesitancy among adults in Kenya

PLOS Global Public Health

Dear Dr. Orangi,

Thank you for submitting your manuscript to PLOS Global Public Health. After careful consideration, we feel that it has merit but does not fully meet PLOS Global Public Health’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Dec 22 2023 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at globalpubhealth@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pgph/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

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Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

We look forward to receiving your revised manuscript.

Kind regards,

Lavanya Vijayasingham, PhD MPH

Academic Editor

PLOS Global Public Health

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Additional Editor Comments (if provided):

Thank you submitting this important research to this journal. We've had a speedy review process with meaningful comments and suggestions on how to enhance the manuscript.

I am recommending major revisions as the collective list of comments is long, and cover the whole manuscript. Nevertheless, I believe these points can be addressed well by the author team.

Overall please focus on:

a) the development and use of the conceptual framework- this appears to be an adaptation rather than a new or novel framework. Please also outline why the domains are independent, why these were necessary to distill from existing literature, how they differ in theory from the definitions of each of the 5Cs, and how they link to the 5Cs which are only discussed in the end of the results section and in the discussion. Please also attribute the components that came from prior models, and describe how

b) rationale for purposefully sampling such a low proportion of unvaccinated people- given the nature of the study and the national vaccinations rates presented. Please outline proportions who were partially vaccinated and their decision to not receive any further dose (not including booster shot- i.e 3rd dose of mRNA type of vaccines etc).

c) emergence of new themes or context specific knowledge that can contribute to tailored design and messaging of vaccination programs or any other health service delivery area, and how these findings are relevant especially since COVID-19 is no longer considered a public health emergency.

Specifically, please also consider and address the following points in the revisions (alongside those from the three reviewers). 

Introduction

1. Ln69 &70: “In Kenya, routinely vaccinating adults is a novel area, that has gained much appreciation since the COVID-19 pandemic”

What about seasonal Influenza? Perhaps elaborate on trends of access and uptake, including within high-risk populations- and reasons why adult vaccination was considered in the country as ‘novel’.

2. Th introduction section will benefit from outlining definitions and literature around adult vaccine hesitancy, contrasting this concept with vaccine acceptance (and discussion around the spectrum). Then discuss specifically for COVID-19 in global and LMIC context, before discussing the Kenyan context.

3. Which COVID-19 vaccines were available in Kenya during this time? What were specific themes of global hesitancy or concerns on each of these class/types of vaccines?

4. As the authors highlight- the COVID-19 is no longer a public health emergency. Please elaborate on why understanding the reasons for COVID-19 vaccine hesitancy is necessary now- perhaps in preparedness for future pandemics? Authors describe its impact on future routine vaccines in lines 85 &6- which adult vaccines?

Methods

1. Please provide rationale- why was a newly developed (or rather- an adapted version of the 5C psychological constructs) conceptual framework necessary? Is this an analytical framework instead?

2. Also, why were the four domains of determinants considered independent?

3. What about time dimension- did time change people’s perception and decisions? Even when they discussed the pandemic retrospectively?

4. How does the participant demographics in each setting reflect the composition in each of the geographical areas?

5. What was the reason for including vaccinated participants in a study about hesitancy- where 80% had at least one dose? How many had 2 doses (fully vaccinated)? Only 16 of all FGD were unvaccinated at time of FGD. Did any of those vaccinated even partially change their minds before first being hesitant, or after receiving the first dose? This speaks about the time component in the conceptual/analytical framework

6. What are characteristics of the 8 healthcare managers and providers?

7. In FGDs, what were observations around who spoke, and who were silent? What were group dynamics observed? How did the identity of the data collector likely influence engagement and discussions- especially tying in with social desirability which is discussed in limitations section.

Results

1. Why were results divided based pre-identified determinant from the scoping reviews, and how did the 5C model feature in the coding and analysis?

2. What were any new emergent codes and themes that fell outside the pre-established framework, and how do these provide new insights especially in the local context?

3. How did narratives from unvaccinated, partially vaccinated and fully vaccinated participants, including those Booster shots differ? How did the different dosing regimes influence decisions and narratives? Please include this data in the FGD participant table.

4. In relation to this- please also provide the proportion of vaccinated, partially vaccinated and fully vaccinated in each FGD group, and how this composition may have influence the discussions by groups. Did unvaccinated people or those chose to be partially vaccinated speak up during group discussion?

5. I think productivity concerns do not necessarily sit under differences in social demographic characteristics- it can be flipped around to be structural since people who work on daily wage will be missing out if they experience side effects or any longer term consequences in comparison to those with jobs that provide some ‘protections’ i.e- paid sick leave etc.

6. Gender, - gender roles and gendered patterns of health-seeking even outside vaccinations, is a notable dimension of uptake and hesitancy- not just a sociodemographic factor- but here biological sex plays a role too- in the quotes there is reference to ‘rumours that they would become impotent’ (ln 221)- this is a sex-related concern, where awareness campaigns have not managed to dispel these known fears. These areas require further in-depth analysis…

7. Myths, health status- the quote on lines 253-255 is an interesting one- that while this person may be seen as high risk of the negative consequences of infection, they are more fearful of the potential negative consequences of the vaccine.

8. The quote on lines 257 to 262 on use in pregnancy speaks about the time factor- that with time and exposure to new information and seeing other like them experience positively is a driver that can address hesitancy, and it also speaks to the importance of awareness building and right messaging.

9. In the introduction, the authors mention adult vaccinations being novel in Kenya, but speak about past experience of other vaccines in the uptake of COVID-19 vaccines, including fear of needles. Please elaborate on the types of adult vaccines that could have led to this, or alternatively with needles- could it also be any medicines administered through syringes?

10. Contextual- discussions in this section relate more to sociocultural influences than context: the role of social media and different sources of information, trusted information source/people- CHV-, religion, faith & traditional knowledge over modern medicines; Here the importance of capacity building and incentivizing CH workers or volunteers is useful to build health systems preparedness and resilience in future crises.

11. The discussion about Kivuti is interesting and is unique to the local context- what is the history of this, and is this discussed in medical anthropology literature?

12. Enforced restrictions as a driver that compelled people to be vaccinated- not necessarily addressed their hesitancy, but they valued their freedom to move, including for work- here another form of productivity concerns is presented. More discussions around policy enforcement as a structural driver is useful but discuss and comment on how it can impact on individual agency a failure to fully address the root of hesitancy. Vaccination is not the same as vaccine acceptance- so it will be important to discuss the influence of mandatory measures here.

13. Quote on line 365- speaks to vaccination programs and the venues or ease of access being a driver.

14. Myths and rumours- the different narratives around population control, long term negative effects and ‘eradication of elderly’ are interesting to prepare for any future epidemics/pandemics

15. The next section is similar- misinformation- how are these different to myths and rumours?

16. Availability of vaccines types is structural- what influenced this and what was available in these two settings? Any differences?

17. In the discussion around vaccine stock or stockouts- please explain why Pfizer was allocated to pregnant & lactating mothers, and why there were stock issues. “Sending them away” speaks to the convenience of access- where lack of stock, and structural factors that influence these barriers prevail.

18. Novelty of adult vaccination is context-based theme here: perhaps seasonal influenza shots are not common? Why? There is an interesting reference to polio by FGD participant (ln 466-467). Are there lessons that can be drawn from historical programs?

19. How were confidence, constraints and complacency identified as main antecedents? There is missing description and discussion of this.

20. Feedback loop and framework method- how did the analysis of themes contribute to the creation of the feedback loop? Please provide more details on process.

21. In the loop diagram, it appears that you are suggesting theoretical propositions or hypothesis that can be later tested. Is this the case? Please review and discuss how the relationships you propose features in current literature, and how it may be a contribution to research in this area.

Discussions

1. The results section is divided based on domains from scoping review but proposition, and now discussions is heavily based on 5Cs.

2. How are drivers of vaccine hesitancy any more complex in Kenya as opposed to any other country, or globally? (Ln 498)

3. Again, the link to lack of confidence, high complacency and constraints (Ln 499) is unclear.

4. The link between vaccine complacency and the lifting of structural restrictions is unclear based on the data and discussions presented in the results section. Again the need to discuss time is important- especially in how it influenced decisions or changing decisions.

5. The importance of gender-sensitive programs for vaccination, and those that address work factors i.e. timing, productivity concerns is important- perhaps a national mandate time away from work, or work based vaccination programs?

6. Consistency of language is useful- is the focus vaccine hesitancy or vaccine uptake? Ln 561

7. Limitations- why or what makes the study not generalizable? Indeed vaccine hesitancy varies across time (which further reiterates my point on the need to review the influence of time, or how decisions changed with time- as it is discussed retrospectively at the time of the data collection). How may have social desirability influenced the participants discussions or even the data that they self-report- i.e their vaccination status?

8. What specifically does the study contribute to knowledge of vaccine hesitancy in LMICs?

9. What are context or regional specific knowledge that requires further research? This could be how traditional remedies are perceived etc.

10. Again, while COVID-19 is no longer a public health emergency- what does this knowledge contribute to beyond COVID-18- perhaps in the future or in other health system areas?

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does this manuscript meet PLOS Global Public Health’s publication criteria? Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe methodologically and ethically rigorous research with conclusions that are appropriately drawn based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Partly

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: N/A

Reviewer #2: N/A

Reviewer #3: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available (please refer to the Data Availability Statement at the start of the manuscript PDF file)?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception. The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS Global Public Health does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Thank you for the opportunity to review this important work. The area of work presented in this paper offers new and valuable insights into global health.

Feedback:

The conceptual framework referred to in the methods section should be introduced in the Introduction section. This is crucial to establish the main argument at the outset of the paper and to emphasize the primary findings discussed in the results section. This linkage between the introduction and the subsequent sections is currently missing and can be enhanced by conducting a more comprehensive review of the existing literature that forms the basis of the conceptual framework.

The results section is organized around the four determinants of vaccine hesitancy. However, the sub-headings (bolded) and the narrative within the results section sometimes diverge, and it would be beneficial to present the information more concisely and regroup it to clearly highlight the four determinants.

The discussion section would benefit from providing deeper insights into how this research aligns with global health initiatives promoting vaccine equity (based on the Results section) and discussing strategies for enhancing vaccine campaigns, especially across low- and middle-income countries (LMICs).

Reviewer #2: Introduction

The introduction successfully sets the global and local context of the COVID-19 pandemic, which provides a backdrop for the study's focus. A research gap in the existing literature is identified, underscoring the need for qualitative studies that offer in-depth insights into vaccination decisions.

In line 61, there's a goal mentioned about vaccinating 100% of the adult population by December 2022. Yet, by March 2023, only 36.7% of adults were vaccinated. It might be useful to question more explicitly why, aside from initial supply-side challenges, this ambitious target was missed so significantly.

The sentence in lines 69-71 regarding the novelty of adult vaccination in Kenya seems a bit indirect. Furthermore, the phrase '...has gained much appreciation…' seems to conflict with the subsequent introduction of vaccine hesitancy. Consider rephrasing for clarity: "Historically in Kenya, routine vaccinations targeted children and adolescents, making adult vaccination a relatively new initiative, further emphasized by the COVID-19 pandemic."

Line 73-75 discusses the definition and complexity of vaccine hesitancy. Consider briefly elaborating on why it was deemed one of the top 10 threats to global health in 2019 to provide readers with context.

In lines 77-79, Kumar et al.'s societal reactions to vaccinations might benefit from a brief explanation or example so readers can understand what each phase entails without referring to the original source.

Methods

The section on "Conceptual framework" offers a detailed breakdown of determinants of vaccine hesitancy. The 5C psychological constructs are well-defined. However, elaborating briefly on how these constructs were adapted specifically for this study may add depth.

In line 121, ’"they influence on or more of the psychological constructs" seems to have a typographical error.

While the spectrum from complete refusal to complete acceptance is mentioned, consider detailing more on the intermediate stages. What exactly constitutes "refusal but not certain" or "acceptance but not certain"? Providing examples or scenarios could enhance comprehension.

Towards the end, it might be useful to add a brief note about the limitations of the conceptual framework or any potential biases that could arise from its use.

Study settings

The section provides a succinct overview of the counties selected for the study. You can offer context as to why it was essential to study urban vs. rural, or high vs. low vaccination coverage.

The term "purposively selected" is used twice. Provide a brief rationale for the purposive selection method used, as readers may not be familiar with its application in this context.

Study design and data collection

Ensure consistency in terminology throughout, for example, ‘health care workers’ and ‘health workers’.

In line 149, the phrase "COVID-19 vaccination status" can be made clearer by specifying whether this refers to individuals who were vaccinated, unvaccinated, or partially vaccinated.

The role of community health volunteers (CHVs) is mentioned in lines 145-147. It would be beneficial to briefly explain why CHVs were chosen for this purpose and their credibility in the community.

The sentence in lines 166-168 repeats the idea of "saturation" twice, which can be redundant.

In Table 1, Ensure that the numbers in the "Summary of FGD participants" match the totals from Kilifi County and Nairobi County.

Results

The organization of results into four determinants of vaccine hesitancy is commendable. This makes it easier to follow and understand the various factors influencing vaccine hesitancy.

Addressing perceptions around comorbidities, pregnancy, and past experiences with vaccinations is relevant in the context of the COVID-19 pandemic. These factors have been topical issues in vaccine uptake discussions globally.

It might be beneficial to contrast the perceptions from urban vs. rural settings more explicitly. This would highlight the unique challenges and drivers in each setting.

The information on cultural and religious beliefs influencing vaccine hesitancy is intriguing. Delving deeper into this topic and providing more details would enhance understanding.

There's a bit of repetition in lines 331-332, where "restrictions" is repeated multiple times; it can be phrased concisely.

In line 356, “COVID-19vaccines” is missing a space.

In lines 483/488, the term "casual loop diagram" appears to be a typographical error.

In line 490, consider changing "then vaccine hesitancy will be high" to "this leads to increased vaccine hesitancy."

While many challenges and concerns are highlighted, there's limited mention of potential solutions or ways the concerns have been addressed, other than CHV efforts. Expanding on measures taken by health officials, NGOs, or local communities would provide a more balanced view.

Discussion

The discussion is logically structured with a focus on vaccine hesitancy's key drivers, the role of communication mediums, the impact of mandates, and constraints. The study context and its relevance two years post-vaccine rollout is adequately established.

The parallels drawn with similar studies from other regions strengthen the argument and contribute to the paper's depth. Mentioning social media's role in shaping vaccine perceptions is crucial in today's context, and this section effectively highlights its impact and the challenge of misinformation.

There's a typographical error in the beginning: "qualitative fi1ndings"

Consider expanding on the "multisectoral approach." While the inclusion of community health workers and religious leaders is mentioned, further elaboration on how these sectors can collaborate might enhance the recommendations' clarity.

Given the importance of combating misinformation on social media, consider suggesting specific strategies or collaborations with tech platforms or leveraging community-driven content to spread accurate information.

Conclusion

The conclusion is concise and to the point, effectively summarizing the discussion's main points. Consider expanding on the "transparent and consistent communication" recommendation, providing tangible steps or examples.

Reviewer #3: 1. What was the rationale of interviewing healthcare managers and providers, as the objective is to determine "decisions around whether or not to receive COVID-19 vaccine and the reasons behind them", as indicated in the introduction. The data seems hardly used as almost all excerpts were from FGDs.

2. In the discussion, the author should discuss impact of starting off their qualitative data analysis using a conceptual framework as opposed to letting the data "speak". Was a mixed approach utilized?

3. The authors purposively selected Kilifi and Nairobi county, based only on vaccination coverage. Given vaccination is largely contextual, and Kenya has 47 diverse counties, do the views represent vaccine hesitancy in Kenya?

4. The distribution of the 8 IDIS is broadly defined as health workers and county managers. Would good to specify which cadres and in what quantity of the 8 respondents given the demographics table is not included. Line 156/7.

5. In the introduction the authors reported that Kenya had a vaccination rate of 36.7%, and specifically indicate that selected counties had vaccination rates of 57.1% and 21.3%. However, the results indicate that 80% of the respondents were vaccinated, with a good majority getting the booster dose. Despite this being a qualitative study, collecting views on vaccination hesitancy should aim to balance those with the outcome, and at the least should have purposively selected based on vaccination status to at least a 50:50 ration to get feedback from majority who did not get vaccinated. This sample is the voice of largely vaccinated people. What dot he unvaccinated (majority in the country and selected counties) have to say? This voice is under represented. Is it the effect of using HCW to recruit study participants?

6. The findings indicate that there was a gender influence on vaccine uptake, especially in the rural area selected, driven by socio-cultural factors. However, it is noted that all FGDs were mixed gender as opposed to gender specific. Do the authors feel that they have accurately captured the weaker gender's perceptional and drivers to vaccination? What safeguards were in place to ensure free and open expression?

7. In the discussion, kindly be sure to tie it to your findings which you seem to have used various lenses. Started off with the conceptual framework with 4 key constructs, once the themes were developed they were further classified based on the 5C model. Hence the discussion should align with whichever framework or model the author would prefer to present, or clearly present both, so that the content is easier to digest.

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

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PLOS Glob Public Health. doi: 10.1371/journal.pgph.0002986.r003

Decision Letter 1

Lavanya Vijayasingham

7 Mar 2024

A qualitative inquiry on drivers of COVID-19 vaccine hesitancy among adults in Kenya

PGPH-D-23-02085R1

Dear Ms Orangi,

We are pleased to inform you that your manuscript 'A qualitative inquiry on drivers of COVID-19 vaccine hesitancy among adults in Kenya' has been provisionally accepted for publication in PLOS Global Public Health.

Before your manuscript can be formally accepted you will need to complete some formatting changes, which you will receive in a follow up email. A member of our team will be in touch with a set of requests.

Please note that your manuscript will not be scheduled for publication until you have made the required changes, so a swift response is appreciated.

IMPORTANT: The editorial review process is now complete. PLOS will only permit corrections to spelling, formatting or significant scientific errors from this point onwards. Requests for major changes, or any which affect the scientific understanding of your work, will cause delays to the publication date of your manuscript.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they'll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact globalpubhealth@plos.org.

Thank you again for supporting Open Access publishing; we are looking forward to publishing your work in PLOS Global Public Health.

Best regards,

Lavanya Vijayasingham, PhD MPH

Academic Editor

PLOS Global Public Health

***********************************************************

Thank you for comprehensively addressing the comments and suggestions provided in the previous round of reviews. The reviewers and I find that the manuscript has been refined to a high standard and are happy to accept it for publication.

Please also submit a COREQ checklist (as supporting material) when finalizing for publication. Congratulations on completing this important research, and wishing you all the best for future research endeavors.

Reviewer Comments (if any, and for reference):

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

Reviewer #3: All comments have been addressed

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2. Does this manuscript meet PLOS Global Public Health’s publication criteria? Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe methodologically and ethically rigorous research with conclusions that are appropriately drawn based on the data presented.

Reviewer #2: Yes

Reviewer #3: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: N/A

Reviewer #3: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available (please refer to the Data Availability Statement at the start of the manuscript PDF file)?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception. The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

Reviewer #3: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS Global Public Health does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

Reviewer #3: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: The manuscript on COVID-19 vaccination rates and hesitancy in Kenya has successfully addressed the detailed comments raised in the previous round of review and is now acceptable for publication in PLOS Global Public Health. The authors have conducted methodologically and ethically rigorous research, presenting their findings in a clearly and coherently, supported by appropriately analyzed interview data. The conclusions are well-founded, offering nuanced insights into the facilitators and barriers to COVID-19 vaccinations within the Kenyan context. The manuscript is technically sound, with a framework analysis that rigorously examines the determinants of vaccine hesitancy and their impact on psychological constructs. It is written in standard English, ensuring that the study is accessible to a broad audience. The authors propose evidence-based, targeted strategies to address vaccine hesitancy, highlighting the importance of trust-building, gender-responsive programs, and a multisectoral approach. This work significantly contributes to our understanding of vaccine hesitancy in Kenya and presents actionable recommendations for increasing vaccination uptake.

Reviewer #3: 1. Correct sentence structure on line 59/60. It does not read like a complete sentence.

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Reviewer #2: Yes: Shazmin Khalid

Reviewer #3: No

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Associated Data

    This section collects any data citations, data availability statements, or supplementary materials included in this article.

    Supplementary Materials

    Attachment

    Submitted filename: Response to Reviewers_2024.02.13.docx

    pgph.0002986.s001.docx (73.2KB, docx)

    Data Availability Statement

    The data presented in this study are available upon reasonable request from the corresponding author through the email dgc@kemri-wellcome.org. Public deposition of the transcripts would breach compliance with the approved protocol. During ethical approval, the transcripts were stated would be available publicly upon reasonable request through KEMRI-Wellcome Trust’s data governance committee through the email dgc@kemri-wellcome.org. This was because at the time of data collection, it was deemed a sensitive topic, it was paramount not to compromise patient privacy, and allow free participation among the respondents. We are therefore kindly requesting for this exemption.


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