Passive enhanced safety surveillance for Vaxigrip and Intanza 15 µg in the United Kingdom and Finland during the northern hemisphere influenza season 2015/16.

Enhanced safety surveillance (ESS) was conducted in the United Kingdom and Finland for Vaxigrip and Intanza 15 µg to comply with the European Medicines Agency interim guidance aimed to detect any potential increase in reactogenicity in near real time following the annual update of the influenza vaccine strain composition. This pilot passive ESS was established to strengthen safety monitoring by facilitating spontaneous vaccinee reports and estimating near real-time vaccinee exposure. The primary objective was to estimate the reporting rates of suspected adverse reactions (ARs) occurring within 7 days post vaccination during the northern hemisphere 2015/16 influenza season. Among the Vaxigrip vaccinees (n = 1,012), 32 (3.2%) reported a total of 122 suspected ARs, including 110 suspected ARs that occurred within 7 days post vaccination. Among the Intanza 15 µg vaccinees (n = 1,017), 31 (3.0%) reported a total of 114 suspected ARs, including 99 that occurred within 7 days post-vaccination. These results were consistent with the known safety profile of the two vaccines and did not show any change in reactogenicity or safety concerns. This passive ESS showed improved data reporting and demonstrated its suitability to health authorities' requirements; further fine tuning of the methodology is under discussion between all stakeholders.

Report from enhanced safety surveillance of two influenza vaccines (Vaxigrip and Intanza 15 µg) in two European countries during influenza season 2016/17 and comparison with 2015/16 season.

Passive enhanced safety surveillance (ESS) was implemented in the United Kingdom and in the Republic of Ireland for Vaxigrip and Intanza 15 µg influenza vaccines during the 2016/17 influenza season. Lessons learned during 2015/16 ESS implementation were integrated and applied towards the current ESS. The primary objective was to estimate the reporting rates of suspected adverse reactions (ARs) occurring within 7 days of vaccination with Vaxigrip or Intanza 15 µg. For Vaxigrip (N = 962), 17 vaccinees (1.8%) reported 59 suspected ARs (6.1%) within 7 days of vaccination. For Intanza 15 µg (N = 1000), 21 vaccinees (2.1%) reported 101 (10.1%) suspected ARs within 7 days of vaccination. No obvious pattern in the type of suspected ARs or their frequency was observed for either vaccine. None of the frequencies of suspected ARs were above the 2015/16 ESS frequencies for Vaxigrip, whereas for Intanza 15 µg only one AR (oropharyngeal pain) crossed the historical threshold. There was no change in reactogenicity and data was consistent with the safety profiles of the two vaccines. The passive ESS experience gained from season to season will help to contribute to a sustainable safety surveillance system of seasonal influenza vaccines early in the season.