The key objective of the EMA enhanced safety surveillance is to rapidly detect a significant increase in the frequency and/or severity of expected reactions (local, systemic or allergic reactions) that may indicate a potential risk.

The Phase 4 study is a passive enhanced safety surveillance aiming to collect prospectively AEIs and/or other AEs experienced within 7 days post-vaccination with GSK's quadrivalent seasonal influenza vaccine, using customized Adverse Drug Reaction cards. Data will be collected via the healthcare provide (HCP) or study medical staff who administer the seasonal influenza vaccination or who provide the informed consent form and the ADR cards.

Results

Results of this Phase 4 clinical trial were published in March 2020.

Results: In 2018, 1060 subjects vaccinated with one dose of GSK's IIV4 were enrolled (all subjects in Belgium and Germany were adults, and 75% and 25% of subjects in Spain were children and adults, respectively). In Spain, 139 eligible children later received a second dose. Overall 1035 subjects completed the study. After dose 1 and dose 2, 98.3% and 100% of subjects, respectively, returned the completed AERC. Over the study period, 43.0% (456/1060 post-dose 1) and 23.7% (33/139 post-dose 2) of subjects reported at least one AE within 7 days after immunization. The most frequently reported categories of AEs were General and Administration Site (e.g. injection site pain, swelling, erythema) and Respiratory Disorders (e.g. rhinorrhoea, cough, nasal congestion). There were no deaths and no serious AEs deemed related to GSK's IIV4.

Conclusion: In compliance with EMA guidance, this study design allowed for near real-time assessment of AEs. No safety signals were detected at any point during the study period. The study supports and confirms the acceptable safety profile of GSK's IIV4.