Hong Kong's Centre for Health Protection (CHP) reported on August 21 a severe paediatric influenza A infection in an 11-year-old boy with underlying illnesses. He developed fever and cough from August 16 and shortness of breath the next day, was admitted to Kwong Wah Hospital after attending its accident and emergency department, and tested positive for influenza A (H3). His diagnosis was influenza A complicated by severe pneumonia and myocarditis, and he remained in the paediatric intensive care unit in serious condition. The CHP's preliminary investigation found no travel history during the incubation period; a household contact recently hospitalised for fever and upper respiratory symptoms also tested positive for influenza A (H3) and has recovered and been discharged.

According to the CHP, Hong Kong entered the influenza season in late June and 11 severe paediatric influenza cases have been recorded since, with six recovered and discharged, one stable, one serious, two critical and one death. It anticipated influenza activity would remain relatively high in the coming weeks and severe cases would increase accordingly, while describing the season as broadly comparable to previous ones and mainly affecting the elderly and children. Influenza A (H1) was the predominant virus detected, followed by A (H3), and genetic analyses found the strains similar to those circulating elsewhere, with no evidence so far of more severe illness or antiviral resistance.

The CHP said procurement for the 2026/27 Seasonal Influenza Vaccination Programmes was complete and preparations were under way. The school outreach programme would introduce an electronic consent form, with school-specific QR codes already distributed and effective, and it encouraged parents to complete the forms so schools could plan activities earlier. It advised parents to watch for deterioration such as shortness of breath, wheezing, blue lips, chest pain, confusion, persistent fever or convulsions.