H1 virus expected to decline in July in HK, H3 virus to rise again in August

Dr.Ivan Hung

18th May 2024 – (Hong Kong) Hong Kong is experiencing persistent high levels of influenza, with experts predicting a rare occurrence of two peaks this season, according to Professor Ivan Hung, the head of the Infectious Diseases section at the University of Hong Kong’s Department of Medicine. The H1N1 virus, which surged in March and April, is expected to decline by July, while the H3N2 strain could hit its peak between August and September.

Professor Hung highlighted the rise in Type B influenza cases, predominantly driven by the H1N1 strain affecting mainly children and the elderly. The severity in children’s cases is particularly concerning, compounded by a lack of prior flu exposure and vaccination during the three-year COVID-19 pandemic. In response, Hung urges early vaccination for children and supports the inclusion of flu vaccines in the Health Department’s immunisation records for children. He also recommends increasing the availability of nasal spray vaccines for this demographic.

In related developments, Hong Kong’s wastewater surveillance has detected the emergence of a new COVID-19 variant, KP.2, similar to the dominant JN.1 strain. However, KP.2 is expected to become the prevalent strain soon due to its higher transmissibility and immune evasion capabilities, though it is believed to cause less severe disease.