Parents' willingness to vaccinate themselves and their children with the booster vaccine against SARS‐CoV‐2: A cross‐sectional study in Puyang city, China

Abstract

We aimed to investigate the hesitancy and willingness of parents to vaccinate themselves and their children with a booster dose against severe acute respiratory syndrome coronavirus 2 and related factors. We conducted a cross‐sectional study in Puyang city, China. The information was collected, including demographic characteristics, willingness to receive a booster dose of coronavirus disease 2019 (COVID‐19) vaccine, and attitudes and concerns toward COVID‐19 and vaccines. Vaccine hesitancy was assessed in individuals completing the first two doses and booster eligible, while vaccine willingness was assessed in those completing the first two doses and not yet booster eligible. Among the participants completing two primary doses while not meeting the booster criteria, 95.4% (1465/1536) and 95.0% (1385/1458) had a willingness to a booster dose of COVID‐19 vaccine for themselves and their children, respectively. Among the participants who met the booster criteria, 40.3% had vaccine hesitancy. Vaccine hesitancy and unwillingness tended to occur in people who were younger, less educated, less healthy, and with unsureness of vaccines' efficacy and adverse events (AE). The younger age of children, children in poorer health, and concern about the efficacy and AE of vaccines contributed to the participants' unwillingness to vaccinate their children. We observed a high willingness to the booster dose of COVID‐19 vaccine both for the parents and their children, regardless of the eligibility to a booster dose. However, 40% of people had delayed vaccination behaviors. The promotion of scientific knowledge of vaccines' effectiveness and safety is needed, especially for people in poor health and parents with young children. Timely disclosure of AE caused by COVID‐19 vaccines and proper aiding offered to people encountering AE are suggested.

1. INTRODUCTION

The pandemic of coronavirus disease 2019 (COVID‐19) caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection has resulted in a heavy burden of morbidity and mortality, as well as socioeconomic costs worldwide. The World Health Organization (WHO) recently estimated that approximately 14.9 million excess deaths were associated directly or indirectly with the pandemic in the period January 2020 to December 2021, most of which were concentrated in South‐East Asia, Europe, and the Americas. ¹ In addition, men and older adults bore more shares of mortality than women and the younger population, respectively. However, an increased number of articles have revealed the long‐term effects besides the morbidity and mortality in the acute phase of the disease. It was estimated about 80% of patients developed at least one long‐term symptom, such as fatigue, headache, and attention disorder. ² Some clinical sequelae such as damage to the heart and lung were also reported. ³ , ⁴ Although the elderly suffer from more deaths and acute illnesses, a modeling study taking account of the morbidity burden of long‐term effects from COVID‐19 concluded that children and adolescents would account for a much higher proportion of morbidity than the older populations when the lifelong symptoms were not mild. ⁵ More attention and efforts should be paid to children and adolescents to protect them from SARS‐CoV‐2 infection and the related sequelae.

A wide variety of vaccines against SARS‐CoV‐2 have been developed and applied with an unprecedented speed under the huge investment by countries. Significant effectivenesses of vaccines in preventing infection, mild/severe disease, and death were observed against original strains in 2020 and the alpha variant in early 2021. ⁶ , ⁷ , ⁸ , ⁹ , ¹⁰ , ¹¹ , ¹² However, the effectiveness of primary immunization with two doses against infection and mild disease decreased modestly as more new variants appeared, such as the beta and delta variants. ¹³ , ¹⁴ , ¹⁵ Since the omicron variant was first announced by the WHO in November 2021, it has spread quickly and dominated in many countries around the world with its much higher transmission rate than the previous variants. ^16,17 The existing vaccines show further weaker protective effectiveness when meeting with the newest variant leading to COVID‐19. However, increasing evidence indicates that the third (booster) dose can provide a protection against symptomatic disease caused by the omicron variant, though the protection waned over time. ¹⁸ , ¹⁹

China has achieved one of the highest COVID‐19 vaccination rates worldwide with two homegrown inactivated whole virus vaccines developed by Sinovac and Sinopharm. ²⁰ China first approved the use of COVID‐19 vaccines in adults aged 18 years and above at the end of 2020 and included adolescents aged 12−17 years and children aged 3−11 years in the vaccination program in July 2021 and October 2021, respectively. ²¹ , ²² Additionally, a booster dose was offered to Chinese adults who had completed their primary vaccination procedure in October 2021. There was growing evidence that children could be safely vaccinated and obtain the similar efficacy as adults. ²³ Several countries including the USA, Israel, the UK, and so forth endorsed or recommended the use of booster doses in adolescents to strengthen the protection against the omicron and other variants. ²³ China has not yet launched a booster shot program for people aged below 18 years. Nevertheless, the recurring outbreaks of COVID‐19 around the country including several occurring in schools, the potential for more variants being evolved, and the desire of protecting children from any severe symptoms caused by SARS‐CoV‐2 infection remain compelling motivations for decision‐makers to implement booster shots in young people in the future.

Numerous papers regarding the acceptance of COVID‐19 vaccines and related factors in adults, patients, and health workers were published. However, few studies focused on the willingness of parents to vaccinate their children with the booster dose of COVID‐19 vaccine. It is also not clear whether there are differences in parents' attitudes toward vaccinating themselves versus their children. We thus performed a cross‐sectional study in China to: (i) describe the parents' willingness of taking a COVID‐19 booster shot toward themselves and their children; (ii) investigate the potential factors for parents to accept a booster shot for themselves and their children; and (iii) evaluate the knowledge and attitudes on COVID‐19 and vaccination among parents at the end of 2021.

2. METHODS

2.1. Design, setting, and population

A cross‐sectional study was conducted from December 6 to 13, 2021 using a convenience sample consisting of parents of children aged 3−17 years in Puyang city, China. Puyang is a medium‐sized city and located in northeastern Henan Province with a 3.77 million permanent population. It has a gross domestic product (GDP) of 177.15 billion Chinese Yuan (CNY) and a per capita GDP of 46 964.4 CNY in 2021, ranking 174 and 230 in the whole 337 cities in China, respectively. In the period of the survey, five types of COVID‐19 vaccines were available in Puyang, including vaccines developed by Anhui Zhifei Longcom, CanSino, Shenzhen Kangtai Biological Products Co, Sinopharm, and Sinovac, where Sinopharm and Sinovac vaccines dominated more than 90% of vaccine sharing. ²⁴ A questionnaire constructed on the Wen‐Juan Xing platform (Changsha Ranxing Information Technology Co., Ltd) was distributed through WeChat to find potential participants. Elementary and middle schools were contacted to post participation messages in the WeChat groups established for teachers to routinely communicate with parents. Individuals were eligible to participate in the survey if they: (1) were parents of children aged 3−17 years, (2) resided in Puyang city, (3) were able to read and write in Chinese on smartphones, and (4) offered informed consent to participate in the study.

2.2. Measures

Six parts of information were collected in the questionnaire (Supporting Information Materials) taking about 10 min: (1) sociodemographic characteristics including gender, age, occupation, educational level, residence location, monthly income, and health status; (2) experience of COVID‐19 vaccination; (3) children' basic information and experience of COVID‐19 vaccination; (4) attitudes and concerns toward vaccinating themselves and their children with the COVID‐19 vaccines; (5) perception of the severity of COVID‐19, the risk of infection, and the efficacy and adverse event (AE) of vaccines; and (6) items to evaluate the anxiety and stress levels of the participants. The above questions involving the children referred to the youngest children of 3−17 years old of the participants. Ten attitude questions about COVID‐19 and vaccines were designed, including the perceived severity of COVID‐19 (Q1−Q2), the perceived risk of infection (Q3−Q4), the confidence to do a vaccination decision (Q5−Q6), the confidence in the efficacy of vaccines (Q7−Q8), and the barriers to take vaccines (Q9−Q10). Attitude questions were given five options ranging from strongly unwilling/disagree to strongly willing/agree. Regarding the question of priority driving factors considered in the decision of vaccination, participants were requested to tick three of the 12 options we offered. Anxiety and stress levels were measured with the anxiety and stress items extracted from the DASS‐21 scale. ²⁵ Several jumps were designed to ensure the necessary and relevant questions were collected for each subject. For example, when one subject answered he/she had not completed the primary immunization of two doses, items regarding the acceptance of booster shots would not appear in the subsequent questions.

2.3. Statistical analysis

Parents' acceptance status of a booster shot against SARS‐CoV‐2 for adults was profiled using vaccine hesitancy and vaccine willingness according to the availability of the booster dose of COVID‐19 vaccine. Vaccine hesitancy was defined as the refusal or at least 1‐month delay of vaccination when one respondent met the booster criteria and was notified to take the booster shot. ²⁶ Vaccine willingness was defined as the answer of agreeing or strongly agreeing to the willingness question of taking a booster shot when one respondent did not meet the booster criteria or was not notified of the booster vaccination. The parents' willingness to the booster dose of COVID‐19 vaccine in children completing the first two doses was merely evaluated because policies in China excluded people less than 18 years old.

Three steps were used to remove low‐quality questionnaires likely providing untrue information. First, 5% of extreme values in answer‐question time were determined by calculating two cutoff values covering 95% of data based on the lognormal distribution of answer‐question time. Participants with an answer‐question time of fewer than 206 s (about 3.4 min) or more than 1527 s (about 25.5 min) were excluded. Second, participants with an age difference of less than 16 years from the children were excluded. Third, participants reporting the age of their children as less than 3 years or more than 17 years in the question “What is the birth year of your youngest kid aged between 3 and 17 years?” were excluded.

Basic characteristics were described using mean and standard deviation for continuous variables and frequency and proportion for categorical variables. Differences in characteristics between participants not hesitant and hesitant, and between participants not willing and willing toward the vaccination of a booster dose of COVID‐19 vaccine were examined with the χ ² test for categorical variables and trend χ ² test for ordinal categorical variables. Variables significantly associated (p < 0.1 in χ ² test or trend χ ² test) with vaccine hesitancy or unwillingness were entered into a multivariable logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI). The logistic regression model was used to explore the related factors on the hesitancy of the parents, the willingness of the parents and the willingness for the children. In attitude questions about COVID‐19 and vaccines, the Wilcoxon signed‐rank test was performed to examine the distribution difference between answers regarding parents and answers regarding children. p < 0.05 denoted statistical significance. The appearance frequency of 12 factors related to a vaccination decision was visualized with R 4.1.2 (R Core Team). All statistical analyses were performed with STATA version 17.0 (Stata Intercooled).

3. RESULTS

3.1. Basic characteristics of all participants

Of the 3790 participants submitting the questionnaire, 3541 met the data screening criteria and were included in the final analysis (Figure 1). The 3541 participants were dominated by the female (86.9%), aged 30−44 years old (85.0%), farmers (45.5%), an educational level of junior high school or below (67.1%), as well as a monthly salary of less than 2000 CNY (about 298 US dollars, 54.1%). In addition, most of them (84.4%) had at least 2 children aged 3−17 years. Almost all the participants (3506/3541, 99.0%) reported to have been vaccinated, and 25.1% (881/3541) were vaccinated with a booster dose of COVID‐19 vaccine. About 54.9% (1945/3541) and 41.2% (1458/3541) of children had received only one dose and two doses, respectively.

Figure 1.

The flow chart of data screening and distribution of demographic characteristics. CNY, Chinese Yuan.

3.2. Difference on hesitancy/willingness toward the booster dose of COVID‐19 vaccine

Among the 1970 participants having the eligibility and access to receiving a booster dose, 793 (40.3%) reported vaccine hesitancy, including 755 planning to receive it at least 1 month later and 38 not planning to (Supporting Information: Table S1). In the bivariate analysis, vaccine hesitancy was associated with a younger age, a lower educational level, self‐reported poorer health, AE experience in previous vaccinations, unsureness toward the validity of the vaccine, and unsureness toward the AE risk by the vaccine. In the multivariable logistic regression model, a higher possibility of vaccine hesitancy was associated with the age of 30−34 (OR: 1.46, 95% CI: 1.03−2.07) and 35−39 years (OR: 1.40, 95% CI: 1.01−1.95) compared with the ≥45 years group (Table 1). The educational level of junior high school or below (OR: 1.40, 95% CI: 1.09−1.81), self‐reported poor or fair health status (OR: 1.52, 95% CI: 1.09−2.12), unsureness toward the validity of vaccines (OR: 1.46, 95% CI: 1.06−2.01), unsureness toward the AE risk caused by vaccines (OR: 1.39, 95% CI: 1.12−1.72) contributed to the booster dose of COVID‐19 vaccine hesitancy.

Table 1.

The correlations between parents' vaccine hesitancy toward the booster dose of COVID‐19 vaccine and tentative risk factors in the multivariable logistic regression model

Variables	% (no of events/N)	OR (95% CI)	p
Age of the parents (years)
<30	43.7 (38/87)	1.46 (0.86−2.49)	0.165
30−34	42.4 (215/507)	1.46 (1.03−2.07)	0.032
35−39	41.9 (337/804)	1.40 (1.01−1.95)	0.043
40−44	35.9 (131/365)	1.14 (0.79−1.65)	0.490
≥45	34.8 (72/207)	Ref.	Ref.
Education level
Junior high school or below	41.4 (525/1267)	1.40 (1.09−1.81)	0.010
Senior high school or technical	41.5 (151/364)	1.36 (0.99−1.86)	0.057
Bachelor or college degree or above	34.5 (117/339)	Ref.	Ref.
Self‐reported health status of the parents
Poor or fair health	50.9 (85/167)	1.52 (1.09−2.12)	0.014
Good health	39.3 (708/1803)	Ref.	Ref.
Self‐reported AE occurrence in previous vaccination against SARS‐CoV‐2 among the parents
Never	39.2 (717/1827)	Ref.	Ref.
Have ever occurred	49.5 (53/107)	1.36 (0.91−2.04)	0.129
Attitude toward the validity of vaccine against SARS‐CoV‐2 infection among adults
Disagree	25.0 (8/32)	0.51 (0.22−1.21)	0.129
Unsure	54.2 (104/192)	1.46 (1.06−2.01)	0.022
Agree	39.0 (681/1746)	Ref.	Ref.
Attitude toward “Receiving SARS‐CoV‐2 vaccines brings high possibility of AE for myself”
Disagree	36.3 (440/1211)	Ref.	Ref.
Unsure	47.6 (267/561)	1.39 (1.12−1.72)	0.003
Agree	43.4 (86/198)	1.28 (0.93−1.74)	0.126

Note: Variables with p < 0.1 in the bivariate analysis were included into the multivariable analysis.

Abbreviations: AE, adverse event; CI, confidence interval; OR, odds ratio; p, p‐value; Ref., reference; SARS‐CoV‐2, severe acute respiratory syndrome coronavirus 2.

Among the 1536 participants not having the eligibility or access to receiving a booster dose, 71 (4.6%) reported unwillingness/unsureness to be vaccinated in the future (Supporting Information: Table S2). In the bivariate analysis, residing in the countryside, self‐reported poorer health, AE experience in previous vaccinations, mild to moderate anxiety, the perceived risk of SARS‐CoV‐2 infection within the next year, disapproval or unsureness toward the validity of vaccine, unsureness toward the waste of time or delay of work caused by vaccination, and unsureness toward the AE risk by the vaccine were associated with the unwilling/unsureness to vaccination. In the multivariable logistic regression model, self‐reported poor or fair health status (OR: 2.86, 95% CI: 1.55−5.26), AE experience in the previous vaccinations (OR: 2.91, 95% CI: 1.50−5.64), the disapproval on vaccines' validity (OR: 5.03, 95% CI: 1.27−19.85), unsureness toward the waste of time or delay of work caused by vaccination (OR: 2.14, 95% CI: 1.01−4.52), and unsureness toward the AE risk caused by vaccines (OR: 3.17, 95% CI: 1.67−6.03) were associated with the unwillingness to receive a booster dose (Table 2).

Table 2.

The correlations between parents' vaccine unwillingness for themselves toward the booster dose of COVID‐19 vaccine and tentative risk factors in the multivariable logistic regression model

Variables	% (no of events/N)	OR (95% CI)	p
Residence place
Town	3.6 (35/964)	Ref.	Ref.
Countryside	6.3 (36/572)	1.62 (0.96−2.75)	0.070
Self‐reported health status of the parents
Poor or fair health	14.0 (24/172)	2.86 (1.55−5.26)	0.001
Good health	3.5 (47/1364)	Ref.	Ref.
Self‐reported AE occurrence in previous vaccination against SARS‐CoV‐2 among the parents
Never	3.6 (49/1358)	Ref.	Ref.
Have ever occurred	11.8 (15/127)	2.91 (1.50−5.64)	0.002
Anxiety level
Normal	4.2 (55/1323)	Ref.	Ref.
Mild to moderate anxiety	9.3 (13/140)	1.14 (0.55−2.37)	0.730
Severe or above anxiety	4.1 (3/73)	0.30 (0.06−1.40)	0.125
Perceived risk of SARS‐CoV‐2 infection within the next year
Low	4.3 (56/1289)	Ref.
Medium	7.8 (15/192)	0.96 (0.47−1.94)	0.905
High	0 (0/55)	‐	‐
Attitude toward the validity of vaccine against SARS‐CoV‐2 infection among adults
Disagree	15.4 (4/26)	5.03 (1.27−19.85)	0.021
Unsure	11.9 (23/194)	1.68 (0.88−3.21)	0.119
Agree	3.3 (44/1316)	Ref.	Ref.
Attitude toward “Receiving SARS‐CoV‐2 vaccines wastes time or delays the work”
Disagree	3.9 (54/1381)	Ref.	Ref.
Unsure	15.4 (16/104)	2.14 (1.01−4.52)	0.046
Agree	2.0 (1/51)	0.85 (0.10−6.83)	0.876
Attitude toward “Receiving SARS‐CoV‐2 vaccines brings high possibility of AE for myself”
Disagree	1.9 (16/848)	Ref.	Ref.
Unsure	8.6 (47/549)	3.17 (1.67−6.03)	<0.001
Agree	5.8 (8/139)	2.29 (0.86−6.06)	0.096

Note: Variables with p < 0.1 in the bivariate analysis were included into the multivariable analysis.

Abbreviations: AE, adverse event; CI, confidence interval; COVID‐19, coronavirus disease 2019; OR, odds ratio; p, p‐value; Ref., reference; SARS‐CoV‐2, severe acute respiratory syndrome coronavirus 2.

Among the 1458 participants answering their willingness status to vaccinate their children with a booster dose in the future, 73 (5.0%) reported unwillingness/unsureness (Supporting Information: Table S3). Among the 668 participants concurrently providing answers regarding the willingness level for themselves and their children, 634 (94.9%) showed willingness and 18 (2.7%) showed unwillingness for both populations, while 13 (1.9%) showed willingness only for themselves excluding children, and 3 (0.4%) showed willingness only for the children excluding themselves (p < 0.001). In the bivariate analysis, the younger age of the children, the poorer health of the children, parents' disapproval or unsureness toward the validity of vaccine among children, unsureness toward the waste of time or delay of work caused by vaccinating the children, and the perceived risk of AE in children by the vaccine were associated with the unwillingness/unsureness to vaccinate their children. In the multivariable logistic regression model, a higher rate of the parents' unwillingness to vaccinate their children was associated with younger children (6−11 vs. 12−18 years, OR: 2.06, 95% CI: 1.02−4.15), the poor or fair health status of the children (OR: 5.85, 95% CI: 1.83−18.67), the disapproval (OR: 3.75, 95% CI: 1.05−13.45) and unsureness (OR: 5.50, 95% CI: 3.07−9.88) on vaccines' validity, and the approval (OR: 3.56, 95% CI: 1.66−7.61) and unsureness (OR: 1.88, 95% CI: 1.03−3.43) on the high risk of vaccines' AE occurrence in children (Table 3).

Table 3.

The correlations between parents' vaccine unwillingness for their children toward the booster dose of COVID‐19 vaccine and tentative risk factors in the multivariable logistic regression model

Variables	% (no of events/N)	OR (95% CI)	p
Age of kids (years)
3−5	4.5 (9/201)	1.93 (0.24−15.22)	0.534
6−11	5.7 (37/648)	2.06 (1.02−4.15)	0.044
12−18	3.6 (25/687)	Ref.	Ref.
Self‐reported health status of the kids
Poor or fair health	30.8 (8/26)	5.85 (1.83−18.67)	0.003
Good health	4.2 (63/1510)	Ref.	Ref.
Attitude toward the validity of vaccine against SARS‐CoV‐2 infection among children
Disagree	14.8 (4/27)	3.75 (1.05−13.45)	0.043
Unsure	12.0 (23/192)	5.50 (3.07−9.88)	<0.001
Agree	3.3 (44/1317)	Ref.	Ref.
Attitude toward “Vaccinating the kids with SARS‐CoV‐2 vaccines wastes time or delays the work”
Disagree	3.8 (53/1381)	Ref.	Ref.
Unsure	16.4 (17/104)	0.89 (0.41−1.95)	0.779
Agree	2.0 (1/51)	0.34 (0.07−1.57)	0.166
Attitude toward “Receiving SARS‐CoV‐2 vaccines brings high possibility of AE for the kids”
Disagree	1.7 (14/842)	Ref.	Ref.
Unsure	9.0 (50/555)	1.88 (1.03−3.43)	0.039
Agree	5.0 (7/139)	3.56 (1.66−7.61)	0.001

Note: Variables with p < 0.1 in the bivariate analysis were included into the multivariable analysis.

Abbreviations: AE, adverse event; CI, confidence interval; COVID‐19, coronavirus disease 2019; OR, odds ratio; p, p‐value; Ref., reference; SARS‐CoV‐2, severe acute respiratory syndrome coronavirus 2.

3.3. Driving factors of accepting the COVID‐19 vaccines reported by the participants

Of the 10 623 votes cast by 3541 participants, the top four driving factors for the vaccination in both the parents and the children were the effectiveness of vaccines (24.8% for parents and 26.9% for children), the safety of vaccines (21.5% for parents and 26.4% for children), the consequence of SARS‐CoV‐2 infection (16.3% for parents and 16.0% for children), and the risk of SARS‐CoV‐2 infection (15.8% for parents and 15.4% for children) (Figure 2). The top four factors of least concern for vaccination in both the parents and the children were getting rewards after the vaccination, time cost on vaccination, attitude and operating skills of vaccination workers, and vaccination suggestions from people around.

Figure 2.

The priority factors impacting the decision of accepting a booster dose of COVID‐19 vaccine against SARS‐CoV‐2 for the participants and their children. COVID‐19, coronavirus disease 2019; SARS‐CoV‐2, severe acute respiratory syndrome coronavirus 2.

3.4. Participants' attitudes and beliefs toward COVID‐19 and COVID‐19 vaccines

A similar distribution of answers was observed between questions regarding parents and questions regarding the children (all p > 0.05, Figure 3). Most participants (about 85%) agreed that COVID‐19 was a severe disease, and 50% of participants were not willing to let themselves or their children work/study with the close contacts of COVID‐19 patients even if the contacts had been released from quarantine. Only about 3% of participants perceived the risk of SARS‐CoV‐2 infection. About 93% of participants were confident in the vaccination decision they made, while about 66% said they had enough knowledge to do such a decision. More than 80% of participants had the confidence in the efficacy of vaccines. More participants worried about the AE caused by vaccines than the time cost or work delay brought by taking the vaccines (10% vs. 4%, p < 0.001).

Figure 3.

The distribution of answers to questions measuring attitudes toward COVID‐19 and related vaccines among the participants. COVID‐19, coronavirus disease 2019; SARS‐CoV‐2, severe acute respiratory syndrome coronavirus 2.

4. DISCUSSION

We identified the vast majority of participants in this study were willing to accept a booster shot against SARS‐CoV‐2, regardless of the eligibility for the booster dose. No significant difference was observed in the vaccination intention for themselves versus their children. Nevertheless, two‐fifths of participants who were eligible to receive the booster dose of COVID‐19 vaccine exhibited vaccine hesitancy. Vaccine hesitancy tended to happen in people who were younger, less educated, less healthy, and unsure of vaccines' efficacy and potential AE. Among the individuals without booster eligibility, the younger age of children, children's poorer health, and concern about the efficacy and AE of vaccines contributed significantly to the parents' unwillingness to vaccinate their children. The effectiveness and safety of vaccines remained the primary factors influencing people's vaccination acceptance. In addition, most participants regarded COVID‐19 as a severe disease and showed a strong confidence in the vaccines' efficacy, although many of them did not have enough knowledge about vaccines.

Numerous studies in countries outside China showed a lower willingness to the booster dose of COVID‐19 vaccine than our study, ²⁷ , ²⁸ , ²⁹ , ³⁰ , ³¹ , ³² , ³³ , ³⁴ exclusive of one carried out in Japan declaring 97.9% of participants intended to accept a third dose. ³⁵ This finding was consistent with the conclusions drawn in reviews that vaccine acceptance was higher in low‐income countries than in the high‐income ones generally. ³⁶ , ³⁷ There were several studies in China focusing on the hesitancy status toward the booster dose of COVID‐19 vaccines against SARS‐CoV‐2. They reported a varying unwillingness rate ranging from 60% to 93.5% among populations in different cities, ³⁸ , ³⁹ which was also lower than our results. Most of them recruited participants located in metropolitan cities and owning a higher educational level and a higher salary than the country's average. As reported by the national bureau of statistics in China, the personal disposable income per capita of Chinese people in 2021 was about monthly 2498 CNY. ⁴⁰ In addition, the average years of education among Chinese people ≥15 years old were 9.9 (about the first year in senior high school) in 2020. ⁴¹ Therefore, the sample in our study more resembled the overall population structure in China, and may be a typical example to reflect the actual status of vaccine hesitancy and willingness toward the booster dose in general populations who made up the majority of this country. This is supported by the similar result in a large cross‐sectional national study in China, which estimated that 6.1% of populations aged 30−49 years were unwilling to receive a booster dose of COVID‐19 vaccine. ⁴² The difference in results between the other studies in China and ours may be explained by the fact that metropolitan cities usually bear more frequent and severe rebounds of COVID‐19 than the other areas, leading to an adverse impact on the residents' confidence in vaccines' efficacy. ⁴³ , ⁴⁴ In contrast, the participants in our study showed a high confidence level in COVID‐19 vaccines, which might be a critical factor contributing to the higher vaccination willingness.

Few studies reported the respective proportions of people choosing a delayed vaccination versus people refusing to vaccinate. This issue merits the investigation because a highly delayed vaccination does not favor the immunization coverage increase against the virus. In this study, we found a significant difference in the extremely high proportion (about 95%) of willingness among individuals ineligible or without access to a booster dose of COVID‐19 vaccine versus the 40.3% of hesitancy among individuals having the chance. There was a gap between people's willingness and actual action toward the vaccination. People who planned to receive the booster dose at least 1 month later constituted the majority of individuals with vaccine hesitancy. A high willingness level among people did not necessarily mean the coverage of booster immunization would increase rapidly as the delay to vaccination existed among some people.

Perceived susceptibility, severity, benefits, and barriers toward vaccination were common structures to explain the vaccine acceptance. ⁴⁵ In our study, an extremely low perceived susceptibility was observed due to the low‐epidemic status in China, whereas a high belief in disease severity and vaccines' efficacy in addition to few perceived barriers could also contribute to the high willingness to vaccination. Active measures such as grassroots mobilization and extensive publication should be maintained to continuously stimulate the vaccination willingness of the public. Notably, most participants believed COVID‐19 was a severe disease in adults or children, though COVID‐19 did not have a high case fatality rate clinically. This misinformation belief among the general residents might be caused by the long‐term strict prevention and control measures against COVID‐19 in China and the broad spread of misinformation through social media. Concerns about the efficacy and the safety of vaccines remained consistent priority factors for people to generate vaccine hesitancy across studies, ³⁶ including our study. Policymakers and scientists have not proposed pointed recommendations to tackle these concerns. In the long battle between humans and SARS‐CoV‐2, more doses or new vaccines may be needed in addition to the third dose in the future. We should be alert to the potential growing fatigue feelings toward the pandemic in populations. More scientific, accurate, and supportive information about the satisfying protective effects of the booster dose of COVID‐19 vaccines was supposed to be conveyed to the public through established publicity channels such as social media, local hospital physicians, and the government. ⁴⁶ , ⁴⁷ At the same time, in the absence of disclosure and definition of AE by mainstream media, the amplifying effect of misinformation on vaccine AE via social media should be given enough attention. Although the participants in this study showed the strong confidence in vaccines' effectiveness, their attitudes may be easily altered by biased information and rumors. A strong pharmacovigilance system for COVID‐19 vaccines should be established to monitor related AE and disclose them through mainstream media. Dedicated helplines may be set up to provide adequate medical care to people encountering AE caused by vaccines. Besides the safety and effectiveness of COVID‐19 vaccines, studies suggested distrust of government, inefficient government efforts, conspiracy theories and misinformation about COVID‐19 vaccines, low education level and awareness, low salary, and poor influenza‐vaccination history were potential predictors of COVID‐19 vaccine hesitancy globally. ⁴⁸ , ⁴⁹ , ⁵⁰ People's trust in the government, the government's efforts in vaccination promotion, and people's vaccination history of other vaccines were not evaluated in this study, they are needed to be considered in future studies. Low education level was also related to the unwillingness of receiving a COVID‐19 vaccine in this study, while salary level was not found any correlation with vaccine unwillingness or hesitancy. In addition, as found in other studies, vaccine hesitancy was likely to happen in younger populations because severe consequences caused by SARS‐CoV‐2 usually existed in the elderly. ³¹ , ⁴² In contrast, we found the parents were more prudent to vaccinate the younger children. It was also reasonable that the young children with weak immune systems captured parents' attention on potential severe AE. Self‐reported poor health in adults and children was also a common reason for the hesitancy or unwillingness to accept a booster shot. Therefore, the detailed evidence on protective effects and the risk of AE caused by vaccines in special populations including the elderly, children, and people with underlying medical conditions needed to be disclosed and actively promoted to address these concerns.

Our study inevitably exists some limitations. First, the cross‐sectional study impeded us to obtain a causality between outcomes and predictors. Second, though we have taken strict data cleaning, some misleading information reported by the participants could not be entirely recognized and handled. Third, the population sample may not be representative of the situation of the whole country as we did not include the elderly and enough young adults in our survey. Fourth, the willingness to vaccination might change over time, the findings from this study should be referenced cautiously. Additionally, people's preference for COVID‐19 vaccines was not collected in our survey, we thus could not explore its correlation with vaccine hesitancy and willingness.

5. CONCLUSIONS

In summary, our study identified a high willingness to accept the booster dose of COVID‐19 vaccine both for parents themselves and their children in Puyang, China. Considering the impact of the vaccine hesitancy, we should pay more attention to the people with willingness but still delayed vaccination, tailored interventions are needed. The promotion efforts on conveying scientific knowledge and evidence of vaccines' effectiveness and safety to the public are needed urgently, especially for people in poor health and the parents of young children. Timely disclosure of AE caused by COVID‐19 vaccines by establishing a pharmacovigilance system for vaccines and providing proper aiding to people encountering AE are suggested to help ease people's concerns.

AUTHOR CONTRIBUTIONS

Qing‐Bin Lu and Fuqiang Cui conceived and designed the experiments, analyzed the data, reviewed drafts of the paper, and approved the final draft. Yiguo Zhou and Guo‐Xing Li collected and analyzed the data, prepared figures and tables, authored drafts of the paper, and approved the final draft. Tian‐Shuo Zhao, Juan Du, Ming‐Zhu Xie, Lin‐Yi Chen, Jing Zeng, Chao Wang, Bei Liu, and Ya‐Qiong Liu collected the data and reviewed the draft. All authors have approved the final draft and agreed to the published version of the manuscript.

CONFLICT OF INTEREST

The authors declare no conflict of interest.

ETHICS STATEMENT

Data were collected and processed anonymously. All the participants have provided informed consent to join this survey. This study was approved by Peking University Institutional Review Board (IRB00001052‐21132).

Supporting information

Supplementary information.

Zhou Y, Li G‐X, Zhao T‐S, et al. Parents' willingness to vaccinate themselves and their children with the booster vaccine against SARS‐CoV‐2: a cross‐sectional study in Puyang city, China. J Med Virol. 2022;95:e28256. 10.1002/jmv.28256

DATA AVAILABILITY STATEMENT

The data sets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.