Adverse events of interest following influenza vaccination, a comparison of cell culture-based with egg-based alternatives: English sentinel network annual report paper 2019/20.

Simon De Lusignan,F.D.Richard Hobbs,Gayatri Amirthalingam,Alexandra Deeks,Filipa Ferreira,Oluwafunmi Akinyemi,Mark Joy,Manasa Tripathy,Ruby S.M Tsang,Gary Howsam,Julian Sherlock

doi:10.1016/j.lanepe.2021.100029

Abstract

BackgroundThe cell-based quadrivalent influenza vaccine (QIVc) is now offered as an alternative to egg-based quadrivalent (QIVe) and adjuvanted trivalent (aTIV) influenza vaccines in the UK. While post-licensure studies show non-inferiority of cell-based vaccines, it is not known how its safety profile compares to other types of vaccines in real-world use.MethodsWe conducted a retrospective cohort study using computerised medical records from the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) sentinel network database. We used a self-controlled case series design and calculated the relative incidence (RI) of adverse events of interest (AEIs) over different risk periods. We then compared the RIs of AEIs within seven days of vaccination overall and between QIVc and QIVe in the 18–64 years age group, and between QIVc and aTIV in the ≥65 years age group.FindingsThe majority of AEIs occurred within seven days of vaccination, and a seasonal effect was observed. Using QIVc as the reference group, QIVe showed similar incidence of AEIs whereas live attenuated influenza vaccine (LAIV) and aTIV had lower incidence of AEIs. In the stratified analyses, QIVe and aTIV were associated with a 16% lower incidence of AEIs in the seven days post-vaccination in both the 18–64 years and ≥65 years age groups.InterpretationRoutine sentinel network data allow comparisons of safety profiles of equally suitable seasonal influenza vaccines. The higher incidence of AEIs associated with QIVc suggest monitoring of several seasons would allow robust comparisons to be made.FundingPublic Health England.

Highlights

Cell culture-based influenza vaccines may have advantages over traditional egg-based vaccines
The results showed that quadrivalent influenza vaccine (QIVc) and QIVe were associated with a similar incidence of adverse events of interest (AEIs), whereas live attenuated influenza vaccine (LAIV) and adjuvanted trivalent (aTIV) were associated with 43% and 26% lower relative incidence (RI) than QIVc respectively (Table 5)
The results showed that relative to QIVc, QIVe was associated with 16% lower RI of AEIs (RI=0.84, 95% CI 0.78À0.91) (Table 5)

Summary

Introduction

Cell culture-based influenza vaccines may have advantages over traditional egg-based vaccines. Trials that compared cell culture-based and egg-based trivalent influenza vaccines generally reported comparable safety and reactogenicity profiles across various age groups. Two trials that compared cell culture-based quadrivalent influenza vaccine (QIVc) with cell culture-based trivalent influenza vaccines found slightly more frequent solicited adverse events. Post-licensure safety surveillance studies did not find any concerning patterns of adverse events associated with cell culture-based influenza vaccines. While post-licensure studies show non-inferiority of cell-based vaccines, it is not known how its safety profile compares to other types of vaccines in real-world use. Using QIVc as the reference group, QIVe showed similar incidence of AEIs whereas live attenuated influenza vaccine (LAIV) and aTIV had lower incidence of AEIs. In the stratified analyses, QIVe and aTIV were associated with a 16% lower incidence of AEIs in the seven days post-vaccination in both the 18À64 years and 65 years age groups.

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