Adherence of nurses to annual seasonal influenza vaccination over a 5-year period.

BACKGROUND

Healthcare workers (HCWs) are at risk of influenza infection with associated nosocomial transmission. Sustained adherence to seasonal influenza vaccination uptake each year is important in epidemic control.

AIM

To assess the adherence of nurses to seasonal influenza vaccination over 5 years and its associated factors.

METHODS

A cross-sectional study was conducted among nurses after the winter influenza season in Hong Kong in March 2019. Based on influenza vaccine uptake rates in the 2014/15-2018/19 seasons, respondents were stratified into three groups: 'full adherence' (vaccine uptake in five seasons), 'partial adherence' (vaccine uptake in one to four seasons) and 'non-adherence' (no vaccine uptake). Stepwise multi-variable logistic regression was performed to determine the associations between adherence to annual influenza vaccination, respondents' characteristics and considerations for vaccination.

FINDINGS

Of 1306 nurses recruited, the majority were female (88%) with a median age of 36 years (interquartile range 30-46 years). The influenza vaccination uptake rate increased from 36% in the 2014/15 season to 47% in the 2018/19 season. After stratification, 39%, 40% and 21% of respondents were non-adherers, partial adherers and full adherers, respectively. Full adherence was significantly associated with female gender [adjusted odds ratio (aOR) 0.60], age ≥40 years (aOR 2.92), long-term care facility nurse (aOR 0.56), uptake during studentship (aOR 3.83), local prevalence of seasonal influenza (aOR 0.51) and expert opinion (aOR 4.04).

CONCLUSIONS

A limited proportion of nurses were fully adherent to seasonal influenza vaccination. Monitoring adherence, improving access to vaccines, and interventions targeting less-adherent HCWs are crucial.