Brand-specific enhanced safety surveillance of GSK's Fluarix Tetra seasonal influenza vaccine in England: 2017/2018 season.

In compliance with the European Medicine Agency guidance to detect any potential safety concerns associated with influenza vaccination, an enhanced safety surveillance study was conducted in England during the 2017/18 influenza season. The primary objective was to estimate the incidence rates of adverse events occurring within seven days of vaccination with Fluarix Tetra. In nine General Practices, seasonal influenza vaccine was administered to patients according to local guidelines. Events following immunization were collected using customized cards (enhanced component) combined with electronic health records [EHRs] (EHR component) to estimate incidence rates of adverse events experienced post vaccination. The study ran from 01-Sep-2017 to 30-Nov-2017. A total of 23,939 subjects were vaccinated of whom 16,433 received Fluarix Tetra. The cumulative incidence rates of adverse events of interest for Fluarix Tetra were 7.25% [95% CI, 5.95-8.73] for events reported by card alone, and 9.21% [95% CI, 7.37-11.34] when combined with EHR data. The type and frequency of events reported were consistent with the Fluarix Tetra Summary of Product Characteristics. The study supports and confirms the safety profile of Fluarix Tetra. ClinicalTrials.gov number: NCT03278067.