Skip to content

Information on Adverse Events Following Seasonal Influenza Vaccination

Information on Adverse Events Following Seasonal Influenza Vaccination
2026-09-21

The egg-based trivalent influenza vaccines recommended by the Scientific Committee on Vaccine Preventable Diseases (SCVPD) for the 2026-27 season contain the following:

  • an A/Missouri/11/2025 (H1N1)pdm09-like virus
  • an A/Darwin/1454/2025 (H3N2)-like virus
  • a B/Tokyo/EIS13-175/2025 (B/Victoria lineage)-like virus

The cell culture or recombinant-based trivalent influenza vaccines recommended by the SCVPD for the 2026-27 season contain the following:

  • an A/Missouri/11/2025 (H1N1)pdm09-like virus
  • an A/Darwin/1415/2025 (H3N2)-like virus
  • a B/Pennsylvania/14/2025 (B/Victoria lineage)-like virus

Seasonal influenza vaccine is very safe and usually well tolerated apart from occasional soreness, redness or swelling at the injection site (inactivated vaccine and recombinant vaccine).  Some recipients may experience fever, muscle pain, and tiredness.

An adverse event is a health problem that is reported after someone gets vaccinated.  It may or may not have been caused by the vaccine.  Some of these events may occur by chance during the post-vaccination period and are unrelated to vaccination.  Report of adverse event does not mean that a vaccine caused the event.

Number of Guillain-Barré Syndrome (GBS) cases within 5 days and 6 weeks after vaccination and other serious neurological adverse events reported among vaccinated person in 2026/27 season (as of 12 noon, 21 September 2026):

Guillain-Barré Syndrome

Other serious neurological adverse events

0

0

For the number of newly admitted GBS cases in Hong Kong, please click here.