Study throws light on vaccine hesitancy in Singapore

COVID-19 vaccine acceptance is high in Singapore, but there are still a reluctant few who prevent the nation from getting a higher immunization coverage against the infection.

A team of researchers from the Nanyang Technological University (NTU) measured the risk perceptions, distress, trust, vaccination beliefs, and vaccine intentions/behaviours of 1,623 Singaporeans in July 2021 and found that vaccine hesitancy was only 9.9 percent at 6 months following the launch of the adult vaccination programme. [Vaccines 2021;9:1415]

The rate looked good and was lower than rates reported in other countries with similar epidemiological COVID-19 profiles and pandemic responses to Singapore (eg, Japan [43.9 percent], Poland [49.2 percent], and New Zealand [30 percent]). [Lancet Reg Health West Pac 2021;14:100223; Lancet Reg Health West Pac 2021;14:100241; Vaccines 2021;9:876]

Meanwhile, among parents, the hesitancy rate for vaccinating children aged 12–18 years was similarly low at 15.9 percent, given that the data collection was performed a week after the launch of the vaccination programme.

Rates of parental hesitancy reported in other countries were also higher (eg, South Korea [36 percent], Australia [24 percent], US [25 percent]), although this may be attributed to the fact that the studies recruited parents with younger children (0–12 years) for whom vaccination authorization was still pending. [J Korean Med Sci 2021;36:1-12; Lancet Infect Dis 2021;21:e110; Vaccine 2020;38:7668-7673]

The mean age of the cohort surveyed was 45.7 years, and 60.8 percent of the participants were women. Most were Chinese (89.5 percent), employed (57.8 percent), had a postsecondary education or higher (86.0 percent), resided in 4–5 room HDB flats, DBSS/HUDC housing or executive apartments (59.6 percent), and had a monthly household income between SGD 5,000 and 12,999 (50.2 percent). The subset of responders with children between 12 and 18 years old had a similar profile.

Not convinced

Choosing between contracting a potentially deadly respiratory infection and a jab in the arm might seem like the easiest decision one can ever make. Why someone would delay acceptance of a COVID-19 vaccine or refuse it entirely despite availability of vaccination services appears to have many causes and largely differ depending on the vaccination target.

Using an integrated psychosocial model informed by relevant theoretical and empirical work, the NTU researchers identified specific predictors of own vaccine hesitancy and parental hesitancy on children’s vaccination. Adult vaccine hesitancy was mostly driven by concerns about side effects, safety, and hasty development of the vaccines. Factors that predicted low vaccine hesitancy included living with people in poor health, adherence to subjective (social or peer influence) and moral norms (collective responsibility; vaccine benefits self and wider community), and belief that the vaccine is beneficial and necessary.

On the other hand, the odds for parental hesitancy for children’s vaccination were higher among fathers (male gender), participants with lower risk perception of COVID-19, those with lower perceived benefits of the vaccines, those with higher vaccination concerns, and those with perceptions of higher personal necessity for the COVID-19 vaccine.

A nudge in the right direction

Singapore already ranks highly on vaccination targets, and pinpointing the causes of vaccine hesitancy can help policymakers decide where to target their efforts, according to the researchers.

“Patterns of results indicated that health policies and programs could leverage on the high level of vaccine acceptance, and responsively adapt vaccination messages to audiences and towards stages of program rollout or implementation. It is important to address vaccine concerns around safety and efficacy especially when new COVID-19 vaccine initiatives and programs are launched (eg, younger children, booster programs),” they said.

However, over time, with the progression of children COVID-19 vaccinations, concerns around safety and efficacy may wane, and perceptions of value and benefits of vaccination for children may acquire more weight, as shown with adults’ own vaccination, the researchers explained.

“Health communications about vaccinations may therefore need to gradually shift focus from addressing risk perceptions and concerns towards emphasizing vaccination benefits for the individual and the community,” they said.

Additionally, messages that leverage and underscore social responsibility may be particularly effective at increasing vaccine acceptance especially for collectivism-oriented settings such as Singapore and capitalize on the social influences surrounding vaccine hesitancy, as the researchers pointed out.

“More work is warranted to better understand what drives ambivalence and what may drive antivaccination attitudes and decisions. Finally … longitudinal studies are required to understand the changes in vaccine attitudes, intentions and behaviours, and vaccination hesitancy trajectories or profiles over time,” they said.