The Department of Health's Centre for Health Protection today announced that the summer influenza season has concluded. With the winter flu season approaching, the centre strongly urged the public to receive the seasonal influenza vaccination (SIV).

The centre's Controller Edwin Tsui said the latest surveillance data shows that the percentage of respiratory specimens that tested positive for seasonal influenza viruses during the most recent week was 4.08%, while the flu admission rate in public hospitals was 0.23 cases per 10,000 population.

As both indicators have dropped below the baseline levels, the centre confirmed that the summer influenza season has ended.

Hong Kong entered the summer influenza season in September last year and it lasted about four months. The predominant virus circulating during this seasonal flu season was the influenza A (H3) virus strain.

Dr Tsui said that this summer flu season has ended, meaning there was no overlap between the summer and winter influenza seasons.

Furthermore, although there are some antigenic differences between the currently circulating influenza A (H3) virus strain and the virus strain contained in the vaccine, an SIV can still offer protection against the variant strain of subclade K, as well as the influenza A (H1) and influenza B strains included in the vaccine.

As of January 4, over 1.91 million doses of the influenza vaccine were administered under various SIV programmes in the year 2025-26, representing an increase of approximately 4.4% compared with the same period in the previous flu vaccination season.

Regarding schools, vaccination rates among schoolchildren in different age groups are two to 10 percentage points higher compared to the same period last year.

Dr Tsui noted that the SIV coverage rate for children aged six months to under two years is only about 22%. Although this represents an approximate five percentage point increase compared to the same period last year, it is still much lower than that of other age groups.

Through the Primary Healthcare Commission, the centre has urged family doctors to assist in encouraging parents to arrange for their children to receive an SIV.