The impact of repeated vaccination on relative influenza vaccine effectiveness among vaccinated adults in the United Kingdom

Lim, Wey Wen; Cowling, Benjamin J; Nakafero, Georgina; Feng, Shuo; Nguyen-Van-Tam, Jonathan S; Bolt, Hikaru

Abstract

Annual seasonal influenza vaccination is recommended for individuals at high risk of developing post-infection complications in many locations. However, reduced vaccine immunogenicity and effectiveness have been observed among repeat vaccinees in some influenza seasons. We investigated the impact of repeated influenza vaccination on relative vaccine effectiveness (VE) among individuals who were recommended for influenza vaccination in the United Kingdom with a retrospective cohort study using primary healthcare data from the Clinical Practice Research Datalink (CPRD), a primary care database in the United Kingdom. Relative VE was estimated against general practitioner-diagnosed influenza-like illnesses (GP-ILI) and medically attended acute respiratory illnesses (MAARI) among participants who have been repeatedly vaccinated compared with first-time vaccinees using proportional hazards models. Relative VE against MAARI may be reduced for individuals above 65 years old who were vaccinated in the current and previous influenza seasons for some influenza seasons. However, these findings were not conclusive as we could not exclude the possibility of residual confounding in our dataset. The use of routinely collected data from electronic health records to examine the effects of repeated vaccination needs to be complemented with sufficient efforts to include negative control outcomes to rule out residual confounding.

Citation

Lim, W. W., Cowling, B. J., Nakafero, G., Feng, S., Nguyen-Van-Tam, J. S., & Bolt, H. (2022). The impact of repeated vaccination on relative influenza vaccine effectiveness among vaccinated adults in the United Kingdom. Epidemiology and Infection, 150, Article E198. https://doi.org/10.1017/S0950268822001753

• Journal Article Type: Article
• Acceptance Date: Oct 28, 2022
• Online Publication Date: Nov 4, 2022
• Publication Date: Nov 4, 2022
• Deposit Date: Nov 3, 2022
• Publicly Available Date: Nov 3, 2022
• Journal: Epidemiology and Infection
• Print ISSN: 0950-2688
• Electronic ISSN: 1469-4409
• Peer Reviewed: Peer Reviewed
• Volume: 150
• Article Number: E198
• DOI: https://doi.org/10.1017/S0950268822001753
• Keywords: Infectious Diseases; Epidemiology
• Public URL: https://nottingham-repository.worktribe.com/output/13176277
• Publisher URL: https://www.cambridge.org/core/journals/epidemiology-and-infection/article/impact-of-repeated-vaccination-on-relative-influenza-vaccine-effectiveness-among-vaccinated-adults-in-the-united-kingdom/02EAB7A59F7F8D962134EDF1913BF10F