The Willingness of Parents to Vaccinate Their Children Aged from Five to under Twelve Years with COVID-19 Vaccines between February and March 2022 in Vietnam

Behavioural and social drivers of COVID-19 vaccination in Vietnam: a scoping review

BACKGROUND

Understanding of the behavioural and social drivers (BeSD) of vaccination is key to addressing vaccine hesitancy and accessibility issues. Vietnam's national COVID-19 vaccination programme resulted in high uptake of primary doses among adults, but lower booster doses for adults and primary doses for 5-11 years. This scoping review assessed BeSD influencing COVID-19 vaccine uptake in Vietnam to design interventions on reaching the national vaccination targets.

METHOD

We conducted a scoping review by searching PubMed, MedRxiv, LitCOVID, COVID-19 LOVE platform, WHO's COVID-19 research database and seven dominant Vietnamese language medical journals published in English or Vietnamese between 28 December 2019 and 28 November 2022. Data were narratively synthesised and summarised according to the four components of the WHO BeSD framework. The drivers were then mapped along the timeline of COVID-19 vaccine deployment and the evolution of the pandemic in Vietnam.

RESULTS

We identified 680 records, of which 39 met the inclusion criteria comprising 224 204 participants. Adults' intention to receive COVID-19 vaccines for themselves (23 studies) ranged from 58.0% to 98.1%. Parental intention to vaccinate their under 11-year-old children (six studies) ranged from 32.8% to 79.6%. Key drivers of vaccination uptake were perceived susceptibility and severity of disease, perceived vaccine benefits and safety, healthcare worker recommendation, and positive societal perception. Commonly reported COVID-19 vaccines' information sources (six studies) were social and mainstream media (82%-67%), television (72.7%-51.6%) and healthcare workers (47.5%-17.5%). Key drivers of COVID-19 uptake remained consistent for both adults and children despite changes in community transmission and vaccine deployment.

CONCLUSION

Key enablers of vaccine uptake for adults and children included perceived disease severity, perceived vaccine benefits and safety and healthcare worker recommendations. Future studies should assess vaccine communication targeted to these drivers, national policies and political determinants to optimise vaccine uptake.

Updated beliefs and shaken confidence: evidence from vaccine hesitancy caused by experiencing "COVID arm"

BACKGROUND

Public health depends largely on people's knowledge, beliefs, or behaviors regarding their health and medical treatments. Although works based on the health belief model have shown that public beliefs about medical treatments affect willingness to take the treatments, little is known about the effects of changes in beliefs on attitudes toward treatment. How one's past experiences relate to one's beliefs about a given medical treatment is worth considering.

METHODS

We implemented an online panel survey in February 2021 and March 2022 in Japan before and after COVID-19 vaccines were administered to the public within the country. We exploited delayed localized hypersensitivity reactions to COVID-19 vaccines, namely, "COVID arm", as an exogenous shock to investigate the relationship between past negative experiences and current beliefs about medical treatments or science. "COVID arm" was an unexpected side effect and thus likely caused updated beliefs about the vaccine. Out of the nonprobability sample of 15,000 respondents in the first wave in February 2021, 9,668 respondents also responded to the second wave conducted in March 2022. Outcome variables were whether experiencing "COVID arm" affected the respondents' 1) confidence in vaccine safety, 2) willingness to take the next dose of COVID-19 vaccines, 3) acknowledgment of the importance of vaccination, and 4) confidence in science. We measured the impact of experience with "COVID arm" on changes in the probability that survey respondents would respond affirmatively to questions posed about the issues listed above.

RESULTS

Experiencing "COVID arm" significantly lowered confidence in the safety of vaccination by 4.3 percentage points, which was approximately 6% of the sample mean for the first wave, and lowered the probability of taking a second dose of the COVID-19 vaccine by 1.5 percentage points. These adverse impacts were observed after conditioning background characteristics and prior confidence in vaccination. Experiencing "COVID arm" affected neither the acknowledged importance of vaccination nor confidence in science in a statistically significant way.

CONCLUSIONS

An unexpected and uncomfortable shock regarding beliefs about a treatment decreases willingness to take the treatment. An appropriate public health policy should account for this effect.

TRIAL REGISTRATION

The survey was preregistered with the American Economic Association's RCT Registry (Fukai et al., 2022).

Perceived Barriers and Intentions to Receive COVID-19 Vaccines: Psychological Distress as a Moderator

A high vaccination uptake degree is crucial to achieve herd immunity to COVID-19 and restrict the spread of the COVID-19 pandemic. However, little is known about the antecedents that reduce or contribute to shaping the intention to receive COVID-19 vaccines, as well as how psychological distress-a mental health problem-can reinforce or dampen the translation from antecedents into intention to receive COVID-19 vaccines. The objective of this study was to explore the effects of perceived clinical and access barriers, self-efficacy, and attitudes towards COVID-19 vaccines on the intention to receive COVID-19 vaccines. Simultaneously, the moderation effects of psychological distress on this relationship were also examined. Using a sample of 2722 Vietnamese adults and structural equation modeling (SEM), this study illustrated that self-efficacy and attitudes towards COVID-19 vaccines were significantly interrelated with intention to receive COVID-19 vaccines. Self-efficacy, attitudes towards COVID-19 vaccines, and intention to receive COVID-19 vaccines were negatively influenced by perceived access barriers but were positively associated with perceived clinical barriers. Importantly, our study reported that when psychological distress was higher, the link between self-efficacy and intention to receive COVID-19 vaccines will become weaker, but the effect of perceived clinical barriers on intention to receive COVID-19 vaccines will be reinforced. Moreover, self-efficacy and attitudes towards COVID-19 vaccines served as mediators in the linkages between perceived barriers and intention to receive COVID-19 vaccines. Besides providing contributions to the extant COVID-19 vaccine literature, this study provides useful recommendations for practitioners and policymakers to foster adults' COVID-19 vaccine acceptance.