Enhanced Safety Surveillance of GlaxoSmithKline's (GSK's) Quadrivalent Seasonal Influenza Vaccines During the 2018/19 Influenza Season

Prospective data collection starting at Visit 1 (Day 1) and ending at Visit 2 (Day 8 or when the ADR card was returned by mail) for all subjects who have previously been vaccinated against influenza in preceding seasons or aged ≥9 years at the time of vaccination, or ending at Visit 4 (Day 36 or when the last ADR card was returned by mail) for children aged \<9 years who have not previously been vaccinated against influenza in preceding seasons). Subjects had up to 14 days post vaccination to return their ADR card (at the next study visit or by mail).