Early uptake of seasonal influenza vaccines incorporated with pH1N1 strain among regularly vaccinated healthcare workers

Abstract

Objectives: This study aims to assess the vaccination uptake and attitudes of healthcare workers (HCWs) towards seasonal influenza vaccination after incorporating pandemic H1N1 (pH1N1) strain in the vaccines. Methods: A self-administered anonymous questionnaire was issued to nurses registered with any of three collaborating nursing associations in Hong Kong. Results: A total of 709 questionnaires were completed, representing a response rate of 28.4%. The coverage of 2010/11 seasonal influenza vaccines was 24.1%. It was lower than that of 2009/10 seasonal influenza vaccines, in which pH1N1 strain was not yet included (37.1%), but higher than that of monovalent pH1N1 vaccines introduced during the pandemic in 2009 (14.2%). The reduction in the number of vaccinated HCWs varied among sub-groups classified by age, duration of employment, type of contacts with patients or past seasonal influenza vaccination record. Early recipients of the vaccine were more likely to have already been vaccinated in the preceding year (odds ratio (OR)=2.95, 95% confidence interval (95% CI) =1.15–7.59) and showed an intention to be vaccinated in the following year (OR=2.78, 95% CI=1.13–6.83). However, incorporation of pH1N1 strain in trivalent seasonal vaccines did not significantly increase the desire for vaccination. Conclusion: In addition to upholding the efficacy and safety standard of influenza vaccines, compliance and acceptance strategies shall be developed as early as possible, and tailored to the needs of different sub-groups.