Changing socio-demographic determinants of seasonal influenza acceptance in England during the pandemic and a framework for predicting future acceptance

Abstract

Objective: To assess the current level of seasonal influenza vaccine acceptance in England and establish the evolving socio-demographic determinants of seasonal influenza uptake and intent-to-vaccinate behaviours between 2020 and 2022. To provide a framework for predicting future rates of seasonal influenza uptake at sub-national scales in England. Design: Two cross-sectional online surveys analysed using a Bayesian time-series multilevel model followed by poststratification to re-weight against English census data. Setting: England, September 2020 to July 2022. Participants: 28,748 English adults, 18 years of age and older. Main outcome measures Three response variables: whether an individual was offered a seasonal influenza vaccine on the NHS in the last 12 months, whether this offer was accepted, and whether they would accept a seasonal influenza vaccine in the next 12 months. Results: In the 2021-22 flu season, 56.3% of adults in England were offered the seasonal influenza vaccine, marking a significant increase of 10.7 percentage points compared to the 2019-20 season. Notably, acceptance of the seasonal influenza vaccine saw a marked rise during this period, par- ticularly among individuals aged 50 and over. However, intentions to accept the vaccine in the next 12 months showed a slight decline across the entire adult population between 2020 and 2022 surveys, although there was an increase among individuals aged 65 and over. Socio-demographic traits play a significant role in shaping vaccine behaviours, with age, gender, education, ethnicity, and religion influencing the likelihood of being offered the vaccine, accepting it when offered, and intending to receive future vaccinations. Noteworthy differences were observed across demographic groups, with smaller gaps among individuals aged 65 and over, particularly between Black/Black British and White respondents. Of particular concern is waning intent-to-accept behaviours among Asian and Asian British groups, as well as Hindus and Punjabi speakers. Regional disparities also emerged, with estimates for flu vaccine receipt and future intent being lowest in London, especially inner London. Moreover, forecasts generated from 2022 data regarding future flu vaccine uptake correlated well with the observed UK Health Security Agency-reported uptake in the subsequent 2022-23 flu season. Conclusions: The findings underscore the significant progress made in increasing seasonal influenza vaccine uptake among adults in England during the 2021-22 flu season, particularly among the older population. However, despite these improvements, disparities persist across socio-demographic groups, highlighting the need for targeted interventions to address barriers to vaccine acceptance. The slight decline in intention to accept the vaccine in the next 12 months among the general adult population warrants attention and suggests the importance of ongoing efforts to promote vaccine confidence and accessibility. Furthermore, the regional disparities observed emphasize the importance of tailoring vaccination strategies to address specific geographical contexts. The strong correlation between predicted vaccine uptake and observed data indicates the potential utility of pre- dictive modelling in informing public health interventions. Overall, these findings provide valuable insights for policymakers and public health practitioners to enhance influenza vaccination efforts and mitigate the burden of influenza-related illness in England.