#18,419
Although all we get is a barebones report (see chart above), the latest Hong Kong Weekly Avian Influenza Report lists 3 new H9N2 infections (1 adult, 2 children) from 3 different provinces on the Mainland.
H9N2 is poorly controlled in Chinese poultry, despite the use of vaccines (see J. Virus Erad.: Ineffective Control Of LPAI H9N2 By Inactivated Poultry Vaccines - China), which has led to the creation and spread of numerous of genotypes.Over the previous 6 months, China has reported an additional 13 cases (see here, here, and here), with well over 100 reported over the past decade (see FluTrackers list). Most cases are mild, and seroprevalence studies suggest many cases may go undetected.
H9N2 also reassorts with, and often enhances, other novel influenza viruses (including H7N9, H5N1, and H5N6), making it an important co-conspirator (see Vet. Sci.: The Multifaceted Zoonotic Risk of H9N2 Avian Influenza).
Seven years ago, in EID Journal: Two H9N2 Studies Of Note, we looked at two reports which suggested that H9N2 continues to evolve away from current (pre-pandemic and poultry) vaccines and is potentially on a path towards better adaptation to human hosts.
While LPAI H9N2 is admittedly not at the very top of our list of pandemic concerns, the CDC has 2 different lineages (A(H9N2) G1 and A(H9N2) Y280) on their short list of influenza viruses with zoonotic potential (see CDC IRAT SCORE), and several candidate vaccines have been developed.
