The potential for a new pandemic is looming as scientists warn about an overlooked bird flu strain, H9N2, that has shown signs of adaptation to human cells. While cases of person-to-person transmission have not been reported yet, experts are urging for increased surveillance of the virus to prevent a potential outbreak.
In recent years, the focus has been on the avian influenza virus H5N1, which has caused severe illness and fatalities in humans. However, H9N2, the second most common strain of bird flu that infects people, has been largely ignored. With 173 reported infections in people since 1998, mostly in China, experts are calling for more attention to be paid to this lesser-known virus.
Research conducted by Kelvin To and his team at the University of Hong Kong has revealed genetic changes in the H9N2 virus that make it more infectious to human cells. Cell-based experiments have shown that a modern version of the virus collected in 2024 infects human cells more efficiently than a historical sample from 1999. These findings suggest that the virus has adapted to spread among people, although further mutations would be needed for sustained person-to-person transmission.
Michelle Wille, a bird flu expert at the Peter Doherty Institute for Infection and Immunity in Melbourne, emphasizes the importance of increased surveillance and communication about the risks of avian influenza. She notes that infections caused by strains like H9N2, which are considered low pathogenicity, may be going undetected due to a focus on more severe strains like H5N1.
To prevent the potential spread of H9N2, scientists recommend enhanced virus surveillance among mammals in close contact with wild birds or poultry. Concerns have been raised about genetic reassortment in animals infected with multiple viruses, which could lead to the creation of new viruses capable of infecting humans. Previous bird flu outbreaks in humans have been linked to genetic material from H9N2, highlighting the need for proactive monitoring and prevention measures.
As the world grapples with the ongoing threat of pandemics, it is crucial to prioritize research and surveillance of emerging infectious diseases like H9N2. By staying vigilant and proactive in monitoring and addressing potential risks, we can better prepare for and prevent future outbreaks.
