Protecting Against Respiratory Syncytial Virus: An Online Questionnaire Study Exploring UK Parents' Acceptability of Vaccination in Pregnancy or Monoclonal Antibody Administration for Infants.

Background: Maternal vaccination and infant monoclonal antibodies are promising avenues to protect young infants from respiratory syncytial virus (RSV) infection. Successful inclusion into the UK immunization schedule depends on parental acceptability, among other factors.

Methods: An online cross-sectional survey from August to September 2023 exploring the likelihood of accepting, and preference for, either method of RSV prophylaxis, and reasons given for these. A questionnaire was distributed via social media networks to UK participants with a child under the age of 2 years and/or pregnant.

Results: A total of 1620 participants completed the survey. Participants' median age was 33 years [interquartile range (IQR), 31-36], 92% were of White ethnicity. Acceptability was high, but higher for a maternal vaccine than an infant monoclonal antibody (P < 0.0001). Concerns about safety, need for more information and number of vaccines given to infants already were common reasons for hesitancy. Lacking knowledge about RSV was associated with a lower likelihood of accepting either option [maternal vaccine: odds ratio (OR): 0.32, 95% confidence interval (CI): 0.16-0.68, P = 0.002; infant monoclonal antibody: OR: 0.35, 95% CI: 0.19-0.68, P = 0.002], as was identifying as Black, Black British, African or Caribbean ethnic group, or having declined the routinely recommended antenatal vaccines.

Conclusions: While most parents would accept a maternal vaccine or infant monoclonal antibody to protect their infant against RSV, understanding preferences, influencing factors and concerns is essential to optimize immunization programs. This study highlights the information parents require to make an informed choice about RSV protection.