NIH scientists look into pandemic potential of H7 influenza viruses
In a recent study published in mBio, researchers with the National Institute of Allergy and Infectious Diseases, evaluated outbreaks of H7 influenza among birds and mammals and compared H7 viruses with other avian influenza viruses and strains.
The scientists found that in recent decades, avian H7 viruses resulted in multiple influenza outbreaks among poultry in North America and Europe. Since at least 1918, none of the poultry-adapted viruses evolved to infect humans widely or result in a pandemic. Some of the viruses have stably adapted to infect mammals like horses. This suggests the viruses could become adapted to and transmissible among humans.
The novel H7N9 virus shares some genes with the H9N2 influenza virus subtype, a subtype that infected humans. The genetic relatedness between the two subtypes could predispose the virus to more readily adapt to humans than other H7 viruses.
Because the possibility exists that H7N9 or another H7 virus could adapt to infect humans more easily, the scientists said more research must be done on how avian influenza strains adapt to mammals, particularly humans. The researchers also said there must be a better integration of influenza research between veterinary and human public health specialists.