Additional COVID-19 Booster Vaccine Hesitancy Among Healthcare Workers in a Private Teaching Hospital in Hong Kong

Introduction : The emergence of new coronavirus variants during the COVID-19 pandemic necessitates the consideration of additional booster vaccinations for high-risk groups. There is limited understanding about the hesitancy of further COVID-19 booster vaccine among health-care workers (HCWs). This study aims to identify factors contributing to HCWs’ acceptance and hesitancy regarding additional COVID-19 booster vaccination. Method : A cross-sessional online survey was conducted to staff of a private teaching hospital in Hong Kong during the period of Jan-Feb 2024. Demographics data, including profession, years of work experience, residential status, presence of chronic medical conditions, among others, were collected. HCWs were asked their willingness to receive additional COVID-19 booster vaccinations and to specify their preferred vaccine type. The hesitancy of further COVID-19 booster vaccination were assessed using a validated 15-item questionnaire based on 5C scale model (Confidence, Complacency, Constraint, Calculation, Collective responsibility), which explores psychological antecedents of vaccination. Results : One hundred and fifty four out of 1470 eligible staff completed the online questionnaire. Four were excluded due to incomplete questionnaire. Among 150 respondents, 21.3% (n =32) plan to receive and 2.0% (n =3) already received additional COVID booster vaccination in the past 180 days. Most of the willing vaccine respondent (n=16, 50%) plan to receive the monovalent Omicron XBB.1.5 vaccine. Age, years of experience as HCW, history of flu vaccination in the past and willingness to take the current year of influenza vaccine were statistically significant for willingness of additional booster vaccine. High mean confidence score (mean = 5.32, SD = 0.9, p<0.001), low mean complacency score (mean = 2.98, SD = 0.99, p<0.001), high mean score of collective responsibility (mean = 5.63, SD = 0.99, p<0.001) were more willing to be vaccinated with additional COVID-19 booster. Multiple logistic regress analysis performed for the above statistically significant variables noted 21 years or above experience as HCW (OR=4.506, 95% C.I. 1.681-12.078, p=0.003), willingness to receive influenza vaccine in current year 2023-2024 (OR=6.095, 95% C.I. 1.891-19.651, p=0.002), low complacency score (OR=0.406, 95% C.I. 0.247-0.665, p<0.001) were associated with additional COVID-19 booster vaccination. Conclusions : This study provides insights into the factors influencing additional COVID-19 booster vaccination intention among healthcare workers (HCWs) in Hong Kong. Further studies are warranted to explore other COVID-19-specific hesitancy factors and the potential impact of counseling utilizing the 5Cs model on enhancing the vaccination uptake rate.