The double-edged impacts of COVID-19 epidemic on influenza vaccination uptake in nurses in Hong Kong.

ABSTRACT

BACKGROUND: Worldwide, the COVID-19 pandemic has disrupted influenza seasonality and impacted influenza vaccination behaviours. This study examines the patterns of influenza vaccination uptake in nurses during the pre-pandemic seasons and amidst the pandemic in 2020/21 in subtropical Hong Kong. METHODS: In April 2021, a cross-sectional survey was conducted in practising and student nurses. Six patterns were differentiated by their influenza vaccination status in 2020/21 and preceding five seasons (a) resistance throughout, (b) negative change, (c) decreased tendency, (d) increased tendency (e) positive change, and (f) adherence throughout. Participants' characteristics and reasons for vaccination/non-vaccination and their associations with each vaccination pattern were explored using multivariable multinomial regression. RESULTS: Among 1323 nurses (88% female with a median age of 39 years), no substantial change in vaccination uptake was noted from 2019/20 (41%) to 2020/21 (42%). Some 4% were positive-changers who were older at age of ≥50 years (aOR 4.77) and more likely to anticipate a reduced risk of severe disease with COVID-19/influenza co-infection following vaccination (aOR 8.76). Negative-changers made up 3% and were more inclined to perceive an unlikelihood of widespread influenza outbreaks amidst the pandemic (aOR 3.67). Some 26 and 43% remained adherent and resistant to influenza vaccination throughout respectively notwithstanding the COVID-19 outbreak. CONCLUSIONS: In contrast to the increased uptake elsewhere, the stable influenza vaccination coverage among nurses in Hong Kong could be explained by the ubiquity of strict physical distancing regulations, which have deterred vaccination in some nurses that offsets the new uptakes induced by the mild COVID-19 outbreaks.