The Demographics of Vaccine Hesitancy in Shanghai, China

Progress in the control of vaccine-preventable diseases (VPDs) can by stymied by vaccine hesitancy and resultant low uptake of vaccines. Vaccine hesitancy is likely to vary by demographic conditions, educational background, and experiences with diseases and vaccines. Information about the development of vaccine hesitancy in low- and middle-income countries (LMICs) like China is spare, as are data about the phenomenon within specific populations, like migrants. The aim of this study was to describe the features of vaccine hesitancy among parents of young infants and to compare vaccine hesitancy across different demographic groups, in particular between locals and non-locals in Shanghai, China. This is a populous area undergoing rapid economic development and is, consequently, a destination for many internal migrants.

This cross-sectional study utilised a stratified, 2-stage cluster sample. Parents of infants under 3 months of age were surveyed at immunisation clinics in townships throughout Shanghai, generating a population representative of city. Participants completed a paper questionnaire utilising the 10-item Vaccine Hesitancy Scale, which was developed by the World Health Organization (WHO) Strategic Advisory Group of Experts on Immunization (SAGE). Based on internal consistency of scale items, 7 items were grouped into the component "Lack of confidence", and the other 3 items (concerns about side effects, newer vaccines, and the continued use of vaccines for relatively controlled diseases) were analysed individually. The items were then regressed onto demographic variables using a negative binomial model. Data collection occurred between May and September 2017.

In total, 1,188 individuals participated. Locals were 48.3% of the population; non-locals formed the remainder, with 15.8% originally from urban areas and 35.9% originally from rural areas. Rural non-locals reported less personal experience with VPDs (22.8%) compared to locals (24.8%) and urban non-locals (32.9%). The study found that the group of individuals who had more experience with VPDs (locals) had more confidence in vaccines while also expressing more concerns in the riskiness of new vaccines and in the utility of certain vaccines.

Overall, a large majority of parents (69.7%) strongly agreed that vaccines are important for their child's health, and about half strongly agreed that vaccines are a good way to protect their child from disease and that vaccinating their child is important for the health of others. For most other items, parents expressed positive beliefs about vaccines. However, about half of parents somewhat or strongly agreed that new vaccines carried more risks than older vaccines, and 71.6% somewhat or strongly agreed that they were concerned about serious adverse effects.

There was no significant difference in the lack of confidence between locals and urban non-locals, but rural non-locals had less confidence than locals (ß: 0.10, 95% confidence interval (CI): 0.02, 0.18). However, compared to locals, both urban and rural non-locals had fewer concerns about new vaccines being risk or about some vaccines no longer being needed. There were also significant differences by parent type, education, and income. For example, compared to mothers, fathers had less lack of confidence (ß: -0.06, 95% CI: -0.12, -0.01), and individuals living in the outer suburbs (ß: 0.13, 95% CI: 0.01, 0.25) and rural non-locals (ß: 0.10, 95% CI: 0.02, 0.18) had greater lack of confidence in vaccines compared to their urban or local counterparts, respectively. Also, individuals with lower levels of education or lower income levels had greater degrees of belief that new vaccines were riskier, which suggests that vaccination providers may be more effective if they tailor their discussion of vaccines to individuals' educational levels - with special consideration given to discussing the importance of new vaccines and their associated risks with individuals who are less educated.

Some takeaways:

• The 3 items that did not map onto the component "lack of confidence" represent important areas for public health officials to promote. Vaccine messaging could focus on addressing misconceptions about vaccines for diseases no longer common, newer vaccines, and adverse effects associated with vaccination. These messages may need to be separately tailored to locals and non-locals, who have differing concerns.
• Limiting the diffusion of vaccine hesitancy will rely on education of vaccination providers on both the benefits of vaccines and on best practices to communicate with parents and other caregivers. Doctors, who are trusted sources of health information, should briefly provide caregivers with facts about the safety of vaccines and be willing to ask open-ended questions and listen to the concerns of parents.
• Caregivers in this study believed vaccines were important for both their own child's health and for the health of others. It follows that another tactic - to increase confidence in vaccines among caregivers and promote their decision to obtain a vaccine for a child - would be for vaccination providers to talk with them about how some children have a contraindication to vaccination, and so vaccinating one's own child can have a positive impact on other community members.

In conclusion, China's ability to add more vaccines into their vaccination schedule and to promote the distribution of non-mandatory vaccines could be limited by concerns about adverse events following immunisation and the risks of newer vaccines. Countering these concerns will be particularly important in lower educated groups and among non-locals who have more recently moved into a city. These researchers' future research will focus on the relationship between vaccine hesitancy, as quantified through baseline results in this Vaccine Hesitancy Scale, and parents' decision to obtain mandatory and non-mandatory vaccines.