Hong Kong health authorities have warned that the city may experience an earlier onset of its summer influenza season this year, with a potential peak in flu cases as soon as late June or July. The Centre for Health Protection (CHP) reported a rise in influenza activity since May, prompting officials to encourage residents who have not yet been vaccinated to seek immunization promptly.

Dr. Edwin Tsui Lok-kin, controller of the CHP, noted that the previous flu season extended from September through January, but the anticipated winter season did not materialize this year. This unusual pattern, he explained, could lead to an earlier and potentially more severe summer flu season due to lower community immunity. “When there is a prolonged period of low flu activity and low public immunity, the peak transmission rate is actually high,” Tsui said during a recent radio interview.

Surveillance data from May 31 to June 6 indicated an increase in local influenza cases, though activity remained below the established baseline level. In that week, 15 adult cases requiring intensive care or resulting in death were confirmed with laboratory tests, including six fatalities. This represents an increase compared to the previous week, which saw six cases and five deaths. Additionally, eight pediatric cases with flu-related complications were noted, though no deaths among children have been recorded as of June 10.

Vaccination campaigns for the 2025-26 season are ongoing, with the new round officially commencing in September. The government offers free or subsidized flu vaccines to priority groups through its seasonal vaccination programs. Uptake rates vary across age groups, with 53.5% of children aged six months to under six years vaccinated, 75.7% of those aged six to under 12, and 61.4% of children aged 12 to under 18. Among adults, vaccination rates stand at 24.4% for those aged 50 to 64 and 49.1% for seniors aged 65 and above.

Ivan Hung Fan-ngai, chair professor of infectious diseases at the University of Hong Kong, emphasized the importance of timely vaccination, especially given the absence of flu outbreaks for the past six months, which has resulted in reduced antibody levels across the population. Hung urged unvaccinated individuals, particularly elderly people, patients with chronic conditions, and young children, to receive the flu vaccine before the current batch expires later this month.

Authorities continue to monitor influenza trends closely and recommend that all eligible residents prioritize vaccination to mitigate the potential impact of the anticipated earlier flu season.