Hong Kong's flu season differs from many places: there are two peaks a year.
Two peaks
The winter peak is usually January to March or April, and the summer peak around July to August. The exact timing varies year to year and is monitored and reported by the Centre for Health Protection.
The best time to get vaccinated
Ideally from September each year, to build protection before the winter peak. It takes about two weeks after the jab to develop enough antibodies, so the earlier you go, the more timely the protection. Even if you miss September, getting vaccinated during the season is still worthwhile and not too late.
Yearly vaccination is needed
Flu viruses change every year, the vaccine is updated for the strains predicted to circulate, and protection wanes over time, so a yearly dose is recommended.
2025/26 arrangements
The 2025/26 government flu vaccination programmes started in late September, with participating private doctors vaccinating eligible people from 22 September and public vaccination sites from 25 September.
Which one to get
Flu vaccines registered in Hong Kong come in three types: inactivated, live-attenuated nasal spray and recombinant. Which suits you depends on age and health, which you can confirm with a doctor.