The Willingness of Malaysian Parents To Vaccinate Their Children Below 12 Years Old Against COVID-19 – A Large Cross-Sectional Study


 Background:The administration of a new drug such as the COVID-19 vaccine in children could be a major concern for their parents. This study aims to assess the willingness of Malaysian parents to vaccinate their children < 12 years old against COVID-19. Methods:An online cross-sectional study was conducted nationwide in Malaysia from 29th August 2021 to 17th October 2021. Parents with children < 12 years old were recruited by the snowball sampling method. Results:Of the 4,438 survey responses received, 3,528 (79.5%) parents were included in the analysis. Of these parents, 2,598 (73.6%) were willing, 486 (13.8%) were not willing, and 444 (12.6%) were still undecided to vaccinate their children against COVID-19. Those who were single parent [odds ratio (OR): 2.0, 95% confidence internal (CI): 1.32 – 3.04, p = 0.001], had secondary or lower education (OR: 1.5, 95% CI: 1.21 – 1.96, p < 0.001), worked as healthcare worker (OR: 1.7, 95% CI: 1.34 – 2.26, p < 0.001), had significant contact with COVID-19 (OR: 1.3, 95% CI: 1.09 – 1.63, p = 0.006), and already received COVID-19 vaccine (OR: 15.4, 95% CI: 9.76 – 24.33, p < 0.001) were significantly more willing to vaccinate their children against COVID-19. The common reasons given by parents who were willing to vaccinate their children against COVID-19 include vaccination could protect their children (99.4%), the vaccination could protect other family members (99.3%), and the vaccine was effective (98.2%). The common reasons given by parents who were not willing to vaccinate their children against COVID-19 include the uncertainty towards the new vaccine (96.1%), worry about the vaccine contents (93.2%), limited information about the vaccine from the doctors (82.3%), and believed the vaccine was unsafe (79.8%)Conclusions:Nearly three-quarters of Malaysian parents were willing to vaccinate their children < 12 years old against COVID-19. The COVID-19 vaccination history of the parents was the strongest independent predictor for their willingness to vaccinate their children. Future health education should target parents at risk of vaccine refusal or hesitation, focus to address the common reasons for refusing the COVID-19 vaccine, and highlight the benefits of the COVID-19 vaccine.

prone to suffer from long-term side-effects if there are any, because the vaccine is given at a much younger age. Autoimmune, fertility, and tumorigenic are among those concerns.
The administration of the COVID-19 vaccine to Malaysian children < 12 years old will only begin in 2022 and be subjected to the approval of the local authority. Therefore, we decided to conduct this study that aims to assess the willingness of Malaysian parents to vaccinate their children < 12 years old against COVID-19. The sociodemographic and in uencing factors that affect their willingness were also determined.

Materials And Methods: Study Design and Patients
A nationwide cross-sectional study was conducted in Malaysia from 29th August 2021 to 17th October 2021. The inclusion criteria of the study were: aged ≥ 18 years old, parent of child or children < 12 years old, and currently residing in Malaysia. The minimum sample size was 665 subjects, calculated based on the type-1 error of 5%, the absolute error of 5%, and the expected proportion of 48.2% for acceptance rate among parents to allow their children to receive the COVID-19 vaccine. (16) This study was conducted in accordance with the Declaration of Helsinki. Online informed written consent was obtained from every respondent before the commencement of the study. Ethics approval was obtained from the Medical Research and Ethics Committee of the University Malaya Medical Center

Procedure
An online survey was used for the data collection due to the ongoing COVID-19 pandemic in the country. The respondents of the study were recruited using the snowball sampling method. Advertisement and questionnaire in Google forms were sent to the respondents via mobile WhatsApp. They were asked to complete an online consent form after con rming that they understood the purpose, risks, and bene ts of the study. This anonymous self-administered questionnaire was either in English, Malay, or Mandarin languages. The questionnaire took approximately 10-15 minutes to complete. No incentive was offered for completing the questionnaire.
The questionnaire was developed by a group of experts in the COVID-19 vaccine via literature review and discussion, taking into account the local situation and policies. (17)(18)(19)(20)(21) It consisted of three parts: part one -the sociodemographic characteristics and clinical data of the parents, part two -the demographic characteristic and clinical data of the children, and part three -the willingness of the parents to allow their children to take the COVID-19 vaccine, and reasons behind the decision. The sociodemographic characteristics of the parents include age, gender, marital status, region of residence, education level, household income, employment status, whether the respondents were healthcare workers, whether they lived together with the elderly or someone with chronic illness, and the number of children < 12 years old that they had. The clinical data of the parents include whether they had been signi cantly contacted with COVID-19, whether they had been diagnosed with COVID-19, whether their families, relatives, or colleagues had been diagnosed with COVID-19, as well as their COVID-19 vaccination status. The demographic characteristic of the children includes age, while the clinical data was concerned if they had chronic illness. Parents can answer "Yes", "No", or "Unsure" concerning their willingness to vaccinate their children against COVID-19, followed by the reasons for their decision. A dichotomous answer of "Yes" or "No" was used for all the questions for reasons, except for "other reasons" for which a written answer was required.
The region of residence was divided into Central region (Selangor, Kuala Lumpur, and Putrajaya), Southern region (Johor, Melaka and Negeri Sembilan), Northern region (Perak, Penang, Kedah and Perlis), East Coast (Pahang, Kelantan and Terengganu), and Borneo Island (Sabah, Sarawak and Labuan). For household income, B40 was de ned as the lowest 40%, M40 as the middle 40%, and T20 as the top 20% of the family income group in Malaysia. (22) The signi cant contact with COVID-19 was divided into that required quarantine, and that required self-surveillance. The age group of the children was divided into 5 -11 years old, 2 -4 years old, and < 2 years old based on the development and dosage of the COVID-19 vaccine in clinical trials.
For parents who were willing to vaccinate their children against COVID-19, thirteen reasons were listed for them to choose (Supplement Figure 1). Two reasons were regarding vaccine properties, three reasons were regarding the recommendation of the vaccine, three reasons were regarding the severity of COVID-19 in the country, two reasons were regarding targets protected by the vaccine, and three reasons were regarding freedom after vaccination.
For parents who were not willing to vaccinate their children against COVID-19, sixteen reasons were listed for them to choose (Supplement Figure 2). Four reasons were regarding vaccine properties, three reasons were regarding limited information about the vaccine, ve reasons were regarding characteristics of the children, three reasons were regarding post-vaccination freedom was not essential, and one question was regarding the cultural and religious concern.
For parents who were still unsure if will vaccinate their children against COVID-19, thirteen factors that may affect their decision in the future were listed (Supplement Figure 3). Four reasons were regarding vaccine properties, three reasons were regarding recommendation, two reasons were regarding the severity of COVID-19 in the country at that time, three reasons were regarding freedom obtained after vaccination, and one question was regarding outcomes of vaccination program in other countries.

Statistical analysis
Results for the categorical variables were expressed as percentages, while results for the continuous variables were expressed as mean ± standard deviation (SD), or median with interquartile range. Differences in variables were examined between parents who were willing to vaccinate their children against COVID-19 versus those who were not willing or still unsure. Differences in categorical variables were compared using the Chi-Squared test or Fisher Exact test. Differences in continuous variables were compared using an independent t-test or Mann-Whitney U test. Multivariate analyses were performed using logistic regression. A 2-sided p-value of less than 0.05 was considered signi cant in this study. Statistical analyses were performed by using the software package, Statistical Package for the Social Sciences (SPSS for Windows version 25.0, SPSS Inc, Chicago, IL, USA).

Results:
Sociodemographic characteristics and clinical data of the parents and children Of the 4,438 survey responses received, 3,965 (89.3%) respondents agreed to participate in the study.
After excluding 437 (9.8%) respondents who did not have children < 12 years old, the nal sample consisted of 3,528 (79.5%) parents. The sociodemographic characteristics and clinical data of these parents and their children are as shown in Table 1. The mean number of children < 12 years old that they had was 2.0 ± 1.13. 76.6% of parents had children 5 -11 years old, 47.9% of parents had children 2 -4 years old, and 16.1% of parents had children < 2 years old. 3.7% of the parents informed that their children had chronic illness, while another 1.4% of them were not keen to disclose.
The willingness of the parents to vaccinate their children against COVID-19 and factors that in uenced their decision Of the 3,528 parents, 2,598 (73.6%) were willing to vaccinate their children against COVID-19, while the remaining 486 (13.8%) were not willing to vaccinate their children against COVID-19 and 444 (12.6%) were still undecided ( Table 2). The reasons parents willing to vaccinate their children against COVID-19 All the reasons provided in the survey were agreed by the majority of the parents (77.5 -99.4%) as the rationale behind their willingness to vaccinate their children against COVID-19 ( Figure 1). The three most common reasons were COVID-19 vaccination could protect their children (99.4%), the COVID-19 vaccination of their children also could protect other family members (99.3%), and the COVID-19 vaccine was effective (98.2%). Additional reasons that were added by the parents include COVID-19 vaccination in children could contribute to overall herd immunity, and children had di culty adhering to precautionary measures.
The reasons parents were not willing to vaccinate their children against COVID-19 The common reasons that given by parents who were not willing to vaccinate their children against Factors that parents who were still hesitant would like to consider before allowing their children to vaccinate against COVID-19 Other than recommendations in social media (35.3%) and recommendations from families or friends (41.4%), all the factors (70.5 -98.9%) listed in the survey were the main consideration of the parents before allowing their children to vaccinate against COVID-19 ( Figure 3). No additional concern was added by the parents.

Discussion:
In this study that focuses on the willingness of Malaysian parents to allow their children < 12 years old to receive the COVID-19 vaccine, nearly three-quarters of the parents were keen to vaccinate their children. In general, having parents that already received the COVID-19 vaccine was the strongest independent predictor of allowing children to be vaccinated. Other independent predictors of willingness to vaccinate the children include being a single parent, having a lower education level, working as a healthcare worker, and having a history of signi cant exposure to COVID-19. Parents from the Northern zone of the country were less keen to vaccinate their children compare to those from the Central zone.
To date, studies focusing on parents' willingness to vaccinate children pandemic was heavily in uenced by past health behaviour, (40) for example, willingness for vaccination.
Single parents, healthcare workers, and those with a history of signi cant contact in our study were more willing to vaccinate their children against COVID-19 due to a higher level of perceived threat. The in uence of education level on vaccination attitude was con icting. Opel et al and Smith et al attributed higher vaccination hesitancy in parents with higher education to safety concerns. (41,42) The lower vaccination rate and COVID-19 cases in the Northern zone compared to the Central zone during this study was conducted explained the lower willingness of parents there to vaccinate their children.
Common reasons that were given by the parents that are willing to vaccinate their children < 12 years old against COVID-19 include believing the vaccine can protect their children, the vaccine can protect family and others, the vaccine was effective, and if the vaccination was recommended by healthcare workers or government. (19,24) Similar reasons were also given by the parents who were willing to vaccinate their children < 18 years old against COVID-19, with additional reasons of believing the vaccine can help to control pandemic, and the bene ts of vaccination outweigh the harms. (17,20) On the other hand, uncertainty to the new vaccine, the concern of e cacy, side-effect, and safety of the vaccine, as well as perception that children were at lower risk to get COVID-19 were the main reasons parents hesitate or not keen to vaccinate their children < 12 years old or < 18 years old against COVID-19. (17,19,20,23,24) Parents in our study also reported similar reasons for willing and not willing to vaccinate their children against COVID-19, except the outcome of the vaccination program in other countries, and severity of COVID-19 in the community/among children were the main concern among parents who still hesitate. Previous literature had shown acceptance of vaccine was frequently associated with external factors (such as information about vaccine protection, and recommendation of vaccine by healthcare workers or government), while hesitancy and refusal of the vaccine were mainly due to vaccine-speci c factors (such as perceived vaccine safety, e cacy, and disease susceptibility) explained the results observed in the current study. (43) Children comprised 28.3% of Malaysian's population of 32.7 million, of which more than half of them were still < 12 years old. Therefore, the nding of the current study that a quarter of Malaysian parents with children < 12 years were unwilling or hesitate to vaccinate their children against COVID-19 was worrying. Besides, the nding that parents who haven't received their COVID-19 vaccine were at a fteen times higher risk of refusing or hesitating to vaccinate their children against COVID-19 is worth prompt attention. The current study also identi ed vaccine-speci c factors that led to COVID-19 vaccine refusal and hesitancy, as well as external factors that promote a positive attitude towards COVID-19 vaccination.
Based on these ndings, more targeted health education can be planned to mitigate COVID-19 vaccination refusal and hesitancy in parents of children < 12 years old.
First, more health education is needed to increase parents' awareness towards COVID-19 vaccination in children < 12 years old. Its' contents should be comprehensive, multilingual, and layman-friendly in order to reach out to parents from all walks of life. The common channel for Malaysians to obtain COVID-19 vaccine information such as electronic media and social media could be the ideal education platform, while printed materials and face-to-face public talks may still bene t certain populations particularly those from the rural area and less educated. (44) Second, health education should target parents at risk of vaccine refusal or hesitant, such as those who still haven't received the COVID-19 vaccine. This group of parents could be reached on the social platform (such as Facebook and WhatsApp group) that provides inaccurate information to them. A recent study by Johnson et al highlighted Facebook pages that against vaccine were greater in number, cross networking, and more common in parenting or school groups. (45) MySejahtera, a mobile application developed by the Malaysian government to facilitate contact tracing and vaccination of COVID-19 could assist in identifying unvaccinated parents and subsequently deliver correct information to them. Third, health education should focus to address the common reasons for refusing the COVID-19 vaccine, such as uncertainty of new vaccine, worry of vaccine contents, the concern of vaccine safety, and lack of information from the doctors. Fourth, health education should highlight the bene ts of the COVID-19 vaccine thus able to promote more vaccination rollout, such as being able to protect children, being able to protect family and others, as well as the good e cacy. Fifth, experimental and real-world data comparing health outcomes of children < 12 years old that vaccinated versus unvaccinated against COVID-19 should be provided to parents once available.
This is among the very few studies that assess parents' willingness to vaccinate their younger children against COVID-19, and the rst in Malaysia. This study had a large sample size and involved population throughout the country. The reasons why parents were willing, unwilling, and hesitate to vaccinate their children against COVID-19 were comprehensively evaluated, including open-ended questions for them to express opinions. There were several limitations in this study. First, snowball sampling was a nonprobability sampling method. Second, only parents with internet access could participate in this online survey. Third, the respondents from the Northern zone were relatively smaller. Forth, in uenza vaccination history was not assessed because it was not routinely administrated among adults or the younger population in Malaysia. Fifth, the parents' knowledge of COVID-19 and their source of information about COVID-19 was not assessed, which could be a confounding factor.

Conclusions:
Nearly three-quarters of Malaysian parents were willing to vaccinate their children < 12 years old against COVID-19. The COVID-19 vaccination history of the parents was the strongest independent predictor for their willingness to vaccinate their children. Perceived e cacy and protection conferred by the COVID-19 vaccine promote a positive vaccination attitude among the parents, while the uncertainty of new vaccine, the concern of vaccine content and safety, as well as lack of information from the doctors, led to vaccine refusal among them. Therefore, future health education should target parents at risk of vaccine refusal or hesitation, focus to address the common reasons for refusing the COVID-19 vaccine, and highlight the bene ts of the COVID-19 vaccine.
4. Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy and integrity of the work are appropriately investigated and resolved.  Reasons that were given by parents that not willing to vaccinate their children against COVID-19