A mutated influenza virus strain is spreading in Hong Kong, potentially reducing the vaccine’s ability to prevent infection, though experts have stressed that the jabs remain effective in protecting against serious complications.
Advertisement
Warnings from experts came on Thursday after the Centre for Health Protection confirmed that a genetically mutated flu A H3N2 virus strain has “recently emerged in Hong Kong and many other regions”.
“The proportion of the mutated virus strain is rising, and is replacing the [strain before mutation],” said David Hui Shu-cheong, a professor of respiratory medicine at the Chinese University of Hong Kong.
An 11-year-old boy studying at ESF Island School was the latest child to develop serious flu-related complications after testing positive for flu A.
The mutated strain, known as J.2.4, carries seven additional mutations compared with the previous one, J.2.2. It has caused a phenomenon known as antigenic drift – small genetic changes in flu viruses that alter key characteristics.
Advertisement
An inquiry has been made to health authorities regarding the prevalence of the mutated strain during the current flu season, which began in early September.
Although the mutated strain does not appear to cause more severe illness, Hui said it may be more transmissible.