Pediatric Practice Experiences with Second Dose Influenza Vaccination: An AAP Pediatric Research in Office Settings (PROS) Study

Abstract

Objective:

Explore pediatric staff experiences administering the second influenza vaccine dose.

Study design:

Qualitative focus groups/interviews

Methods:

As part of the NIH-funded Flu2Text randomized control trial of text message reminders for second influenza vaccine dose, we conducted seven focus groups and four individual interviews (n=39 participants total) with clinicians and staff from participating practices from the American Academy of Pediatrics’ Pediatric Research in Office Settings (PROS) Network. Of 37 participating practices, 10 were selected through stratified sampling of practices with highest (n=5) and lowest (n=5) RCT effect sizes. A semi-structured discussion guide included questions that addressed parental, practice, and health system barriers/facilitators to second influenza vaccine dose administration. Using the Systems Model of Clinical Preventive Care as a conceptual framework, two investigators independently coded transcripts (K=.86, high agreement) with NVivo 12 Plus. Coding inconsistencies were resolved by consensus.

Results:

Clinicians/staff reported that administering the second influenza vaccine dose in a season was more complex than other childhood vaccines. They highlighted parental uncertainty about the need for the second dose and the difficulty and inconvenience of bringing children back to the office as important barriers. Caregiver-staff relationships were perceived as helpful in getting children vaccinated with their second dose and vaccine reminders were seen as important cues-to-action.

Conclusion:

Ensuring receipt of two doses of the influenza vaccine in a given season presents unique challenges. Themes identified provide a framework for understanding opportunities to bolster second dose receipt including explaining why two doses are needed, offering flexible hours for vaccination, and sending vaccine reminders.

Introduction

Each influenza season, young children are at increased risk of developing severe complications from influenza compared to older children and adults.¹ The 2019-20 influenza season, before being abruptly shortened through COVID-19 protection measures,² was still one of the deadliest on record, with 189 pediatric deaths.³ Children 0-4 years old were the age group with the second highest hospitalization rates after those 65 years old and older.³ Given the elevated risk of severe disease among young children, it is imperative that they are adequately protected before influenza peaks each season. Receipt of ≥1 dose of influenza vaccine in the 2022-2023 season was 65.6% for children 6-59 months and 59.3% for children 5-12 years.⁴ Furthermore, it is recommended that children 6 months through 8 years old who are either receiving their first influenza dose or who have not received at least two previous doses or whose influenza vaccine status is unknown receive two doses of the influenza vaccine at least 4 weeks apart to have an adequate immune response to confer full protection.^5–7 However, studies have shown only 40 to 60% of those who receive the first dose go on to receive the needed second dose.^8,9

Seasonal influenza activity typically begins in October or November and peaks between December and February,¹⁰ giving healthcare personnel a narrow window of time to protect their young patients. Successful and timely administration of both doses of the influenza vaccine requires adequate preparation, organization, and cooperation between vaccine administrators (e.g., pediatric offices) and child caregivers. The goal is for children to be fully protected before influenza begins circulating. Given the documented parental hesitancy about the influenza vaccine¹¹ compounded with recent vaccine-resistant sentiment in response to COVID-19 vaccine rollout,¹² understanding factors affecting influenza vaccine administration is of vital importance in ensuring second dose vaccination happens as seamlessly as possible.

Despite the imperative to employ effective tools and strategies in primary care practices, there is little in the literature exploring the multi-level barriers and facilitators to second dose influenza administration in pediatric settings. Much more is known about factors affecting seasonal influenza vaccination such as misperception about need for influenza vaccine, severity of influenza, and vaccine effectiveness, as well as concerns related to the number of total vaccines due, side effects, and logistical issues.^13,14 To address this knowledge gap, we used the Systems Model of Clinical Preventive Care,¹⁵ which focuses on factors involved in the provision and receipt of clinical preventive care, to explore pediatric clinician and medical staff experiences regarding practice and parent factors that affect second dose influenza vaccination.

Methods

Setting and Participants

All study activities were conducted as a part of the Flu2Text study, a randomized controlled trial (RCT) assessing the impact of text-message vaccine reminders for the second dose of influenza vaccine, funded through the National Institutes of Health (NIH) (clinicaltrials.gov: NCT03287830; grant [R01HD086045]).¹⁶ From July to August 2019, following data collection for the RCT, practices were identified for this sub-study based on the stratified sampling of all primary care practices (n= 39 involved in the second season of the RCT (2018-19). Ten practices — those with the highest (n=5) and lowest (n=5) effect sizes for improvement in second dose vaccine receipt with text message reminders — were invited to participate; sampling was based on the primary outcome of the overall intervention study to obtain potentially contrasting perspectives. Of note, in the RCT randomization occurred on the individual child level. All participating practices were members of the American Academy of Pediatrics’ (AAP) Pediatric Research in Office Settings (PROS) primary care practice-based research network.¹⁷ Interviews (n= 4) and focus groups (n= 7 with a total of 35 people) (n=39, including 16 pediatricians, 8 nurse practitioners, 1 physician assistant, 4 nurses, 5 medical assistants, and 5 practice staff) were conducted via telephone by two study staff (EN and CW), who are experienced in qualitative research. There were 11 participants from practices with the highest effect size, and 28 from practices with the lowest effect size. Choice of focus group versus interview was based on participant availability and responses analyzed were integrated from both sources. All participants were verbally consented and assured that their participation was voluntary and that their confidentiality would be protected. For their involvement, participants were provided with lunch. The study was approved by the Institutional Review Boards at Columbia University Irving Medical Center, the Children’s Hospital of Philadelphia (CHOP), and the AAP.

Data Collection and Analysis

Study team members used a semi-structured discussion guide to explore topics such as facilitators and barriers to administering the second influenza dose, current and desired vaccination processes, and clinician and staff perceptions of parent experiences with second dose vaccination. Focus groups ranged from 30 to 60 minutes and individual interviews ranged from 25 to 45 minutes. All focus groups and interviews were audio recorded by the research staff and professionally transcribed.

After data collection, two team members (CW and EN) reviewed the transcripts and conducted a content analysis to identify commonly expressed themes. A codebook was developed incorporating feedback from the other members of the study team. The two team members (CW and EN) then independently coded transcripts using NVivo 12 Plus (QSR International) and obtained high agreement (K=.86). Coding inconsistencies were reviewed (by CW and EN) and all were resolved by consensus. Identified themes were organized using the constructs in the Systems Model of Clinical Preventive Care as a framework to explore practice and perceived parent-level factors that affect the delivery and receipt of the second influenza vaccine dose. The Systems Model of Clinical Preventive Care captures the dynamic interactions that influence patients and clinicians in regards to the completion of a preventive care behavior.¹⁵ This model focuses on the impact of the following 6 factors/domains on the preventive health behavior (i.e., vaccination): (1) predisposing factors, (2) reinforcing factors, (3) enabling factors, (4) healthcare delivery system/organizational factors, (5) preventive activity behaviors, and (6) situational factors.

Results

Demographics

Three practices were located in the Southern region of the United States, one in the Midwest, two in the Northeast, and four in the West; additionally, four practices were rural, four were suburban, and two were urban. Practices were evenly split on their patient insurance mix distribution, with half of the practices (n=5) serving children with predominantly commercial insurance and half (n=5) serving children who were mainly publicly insured (Table 1). Seven practices set aside times or had extra hours when children could come to the office specifically for influenza vaccination either via appointment or walk-in.

Table 1:

Focus Group/Interview Characteristics

	N= 10 practices
Region of Practice
South	3
Midwest	1
West	4
Northeast	2
Urbanicity of Practice
Urban	2
Suburban	4
Rural	4
Practice Type by Patient Insurance Status *
Mostly Public	5
Mostly Commercial	5
Participant Type
Pediatricians	16
Nurse Practitioners	8
Physician Assistant	1
Nurses	4
Medical Assistant	5
Practice Staff	5

^*Practice insurance type is based on the insurance status of those enrolled in the associated randomized control trial (N=1,829)

Preventive Behavior

Overall, participants expressed how the influenza vaccine - including the second dose - appeared to be different than other routine vaccinations, making it difficult to manage:

And the flu vaccine every year presents all kinds of challenges for how to best do it and it’s just so difficult. It’s a different event. I think…the second dose is a challenge.

This difference and the accompanying challenges were further explored along with the other themes from the Systems Model of Clinical Preventive Care (Table 2).

Table 2:

Systems Model of Preventative Care¹⁵ Domain: Themes Pertaining to Second Dose Administration Experiences

Systems Model of Preventative Care Domains	Key Themes	Quotes from Practice Clinicians and Staff
Preventive Behavior	Influenza Vaccine as Distinct Challenge	And the flu vaccine every year…presents all kinds of challenges for how to best do it and it’s just so difficult…It’s a different event. I think – one of the things at our practice – the second dose is a challenge.
Predisposing Factors	General Influenza Vaccine Hesitancy	I mean, we certainly all have some patients who are hesitant about the flu vaccine and that would include for their newborns.
	Second Vaccine Dose Hesitancy	…I mean it’s a small, very small percent that have vaccine hesitancy and [question] ‘do I really need the second dose?’
Preventive Activity Factors	Side Effect Fears	We just had – we had the one parent. That was the only one. She refused to do the second because she said there were side effects from the first.
	Knowledge About Need for Second Dose	One of my problems is I try to tell parents, ‘you know you have to come back in a month for the second flu vaccine.’ And there was a lot of like, ‘why do I have to do that?’
Healthcare Delivery Organizational Factors	Vaccine Visit Scheduling	Lots of parents…didn’t plan for that extra visit at seven months…So, I think that was probably the hardest thing is trying to get people to come in for vaccines.
	Vaccine Supply	We ran out pretty – actually, pretty early. And we had even ordered more than we had the year before. And then we couldn’t get anymore. So, no, that was a problem.
	Transportation issues	They should have been back a month later and it might have been three months later. ‘Oh, I thought you wanted to get –’ ‘oh, we do, but we couldn’t get a ride,’ that kind of thing.
	Influenza Vaccine Clinics	We do flu clinics on the weekends sometimes, too, so that was helpful to work with their schedules… It was by appointment with additional hours. Yeah, we probably saw a couple hundred kids in those –
Enabling Factors	Parent-Clinician Relationship	–… it was easy for me to explain how important the second dose was to improve the child’s immunity and protection. And there was very good acceptance. But so much of that, I think, is the relationship you have with your patients.
Situational Factors/Cues to Action	Vaccine Reminders	I think a lot of the first-time parents don’t realize that the children need the re-booster. So I think it was really effective in that way…I think that they liked best that they were reminded and that they didn’t have to remember that they had an appointment coming up that they scheduled prior because they had the reminder from the text message.

Predisposing and Reinforcing Factors

Pediatric clinicians and staff shared that there is an overall influenza vaccine hesitancy, which could potentially affect getting the second dose:

So, I think the biggest thing is that there’s just some people that just decide they don’t want to do the flu shot, ever…if they agreed to get the first one that was[n’t] necessarily a problem other than the fact that of course, who wants to give their child another immunization?

Preventive Activity Factors

Participants reported that families wanted to know why there was a need for two doses:

There’d be a 5-year-old, and it’s like, ‘oh, you’ve only had one flu vaccine this year and you’ve never had a flu vaccine before, do you need a second one?’ And parents were like, ‘oh, no, he just had one.’ ‘No, no, he needs another one in a month.’ ‘Well, why? … Why do I need to come back in a month, I’m not [going to] do this.’ And they thought they were doing the right thing in giving the first flu vaccine. And then you tell them, now you have to get another one.

Participants also shared that, for a small number of caregivers, perceptions about influenza vaccine safety and its side effects could present challenges even for second dose administration, especially if a child had a side effect after the first dose:

We just had – we had the one parent. That was the only one. She refused to do the second because she said there were side effects from the first.

Finally, some caregivers were also described as being concerned about the number of vaccine doses at a young age and a second influenza dose could add to that number:

Yeah, they’re worried about the number [of shots] at that young age….

Healthcare Delivery Organizational Factors

In addition to clinicians and staff reporting that they receive questions from parents about the need for a second dose, respondents expressed that some parents of young children were not expecting to have another visit outside of the outlined well-child schedule, especially one so soon after the first:

…A lot of parents don’t understand… you have your nine-month visit, and now you have to come back in a month, and then you have to come back at 12 months…

…We gave most of it at the six-month well visit, and so the next visit wasn’t usually scheduled until nine months. So, a lot of families really didn’t plan for that extra visit at seven months. We also don’t do many vaccines not at well visits. So, I think that was probably the hardest thing is trying to get people to come in for vaccines [outside the regular visit schedule].

Clinicians also reported sometimes parents had particular concerns about the potential inconvenience of office visits, as well as barriers for returning such as transportation needs:

…You had to come back for an appointment to get this second vaccine dose. And then parents were like, ‘well, will I be able to just get in and get out, or will it be like today where I had to wait a half hour?’… And once again, that’s our – that’s a system problem. I mean, we just have to figure out a better way…..– I hear people have walk-in flu vaccine clinics. And we just don’t have the staff to do that.’

Vaccine supply shortages also repeatedly came up as a barrier to second dose vaccine administration:

But those were definitely points where you ran into problems where you didn’t have the second dose to give, or even the first dose to give. And that was always a hard thing.

Enabling Factors

Some respondents reported that their relationships with families at their practice helped them administer the second dose as well as provide vaccine education:

…It was easy for me to explain how important the second dose was to improve the child’s immunity and protection. And there was very good acceptance. But so much of that, I think, is the relationship you have with your patients.

Situational Factors / Cues to Action

Nearly all respondents expressed vaccine reminders as a desired cue-to-action for parents. Pediatric clinical staff found that the study text message reminders worked to remind parents not only about the needed dose but also why it was needed:

Because I do think that it – even parents that understand that, it’s so easy to just get caught up in the day to day if you don’t have a reminder that says, ‘okay, it’s time to go get your second dose of flu’ or whatever. It’s easy to get caught up in everything else that life comes – or brings your way. So, I think it..[can]…lead to decreased questions about why is this necessary. And parents ha[ve] a better understanding about the need for the second dose.

Discussion

In this study, clinicians and staff reported that receipt of second dose of influenza vaccine is a unique challenge for pediatric practices especially given the two doses being needed within a short time frame and ideally in the fall for timely protection. Some themes elicited were similar to those reported generally for the influenza vaccine, such as vaccine hesitancy, perceptions about influenza vaccine safety and its side effects, concerns about multiple vaccine doses at a young age, and the importance of the clinician-parent relationship.¹⁸ However, unique to this particular need for two doses of influenza vaccine in a season, clinicians and staff reported specific educational gaps about why a second dose was needed, as well as added difficulties for families regarding the inconvenience of attending another potentially off-cycle office visit, especially so soon after the first influenza vaccine dose. Lessons learned may also be helpful for other multi-dose vaccines in which the ideal timing of a subsequent dose may not generally align with a routine well visit.

Lack of parental initial information about the need for both doses of the influenza vaccine repeatedly was perceived by respondents as one of the second dose vaccination barriers. However, receipt of both doses is important as receiving the second dose nearly halves the odds of lab-confirmed influenza compared to receiving only one dose.⁶ In this study, clinician-parent relationship came up as a facilitating factor for the second dose vaccination. Participating clinicians and staff reported integrating influenza vaccination education into their conversations with caregivers to facilitate second dose vaccination uptake. This action is an effective component in addressing vaccine hesitancy¹⁹ as it works to combat misinformation and educate on the importance of a vaccine.²⁰ This is consistent with other studies that have identified healthcare providers as trusted sources for vaccine information by caregivers and one of the most important sources of influence on patient vaccine decision-making^21–26 It may therefore be particularly important that clinicians take the time to explain to families why the two doses are needed and strongly recommend returning for the second dose.

Decreasing logistical barriers affecting families returning for the second dose was also highlighted. The AAP endorses using walk-in influenza clinics and/or extending hours beyond routine times during peak vaccination periods as useful for promoting vaccine uptake.²⁷ Some of the practices in our sample offered dedicated influenza clinics during non-regular hours, like evenings or weekends, and found them beneficial to help manage office visit flow during a busy influenza season and accommodate parent schedules. Walk-in vaccine hours could be particularly important for caregivers with healthcare access limitations, giving caregivers the flexibility to come in at their own convenience. This change in scheduling in turn may increase second dose vaccination administration and lower the chance of a “no-show”.

Pediatric clinicians and staff also reported that the trial’s vaccine text message reminders were helpful not only to remind parents about the needed dose, but also to explain why it was needed. Vaccine reminders function as a cues-to-action and have been found to have a positive effect on influenza vaccination uptake in pediatrics settings,²⁸ particularly for the second dose.²⁹ These messages can also be helpful to recall families when practices have vaccine supply issues, which were common in our subsample of practices. All practices in our sample were sites for our larger Flu2Text trial,¹⁶ a second dose text message reminder study. Many individuals were interested in continuing automated text-message second dose reminders for their practices beyond the scope of the study.

This study had several limitations. All participants were part of a trial of text message reminders for the second dose of influenza vaccine which occurred prior to the pandemic and are not representative of the perspectives of all pediatric clinicians or staff. Additionally, while this study involved a convenience sample of participants in many states, it is exploratory in nature and not nationally representative. The experiences of caregivers are perceptions of the pediatric clinicians and other medical staff in the study and were not empirically measured or observed behaviors. Finally, during transcription, the roles of clinicians and other medical staff were blinded and therefore comments cannot be separated out by role. Despite these limitations, this study does provide important new and potentially actionable items that pediatric practices could consider to help promote second dose influenza vaccination completion.

Conclusion

Ensuring receipt of two doses of the influenza vaccine in a given season presents unique challenges. Themes identified provide a framework for understanding challenges and opportunities to bolster second dose influenza vaccination. They also highlight important potential actions including explaining to families why two doses are needed, offering flexible hours for vaccination, and sending vaccine reminders.