Hong Kong's Centre for Health Protection (CHP) reported on September 5, 2026 that it had recorded three cases of severe paediatric influenza infection, all in children with good past health. A six-year-old girl was in critical condition with influenza A complicated by encephalopathy, and a three-year-old girl was in serious condition with influenza A complicated by septic shock. A 15-year-old boy was in serious condition with influenza B complicated by septic shock.

Preliminary investigation found no travel history among the three during their incubation periods, and household contacts had recently remained asymptomatic. Two classmates of the six-year-old girl had recently developed mild influenza symptoms without needing hospitalisation, and the CHP advised the school to take infection control measures.

Separately, Dr Edwin Tsui, the CHP's Controller, said that since late June a cumulative total of 16 severe paediatric influenza cases had been recorded. Of these, eight patients had recovered and been discharged, two were stable, three were serious, two were critical and one had died. The CHP said Hong Kong entered the influenza season in late June, with activity rising further the previous week and remaining high. The 2026/27 Seasonal Influenza Vaccination Programmes were scheduled to begin on September 17, and around 80 schools had so far scheduled outreach activities in September.