#18,076
Although it will be primarily of interest to researchers and scientists, overnight the WHO published a detailed report on the genetic and antigenic characteristics of the H5N1 virus recently identified in American dairy cattle.
These lengthy and and often ponderous scientific reports don't lend themselves to reading in a blog format (the 3rd paragraph has 475 words!), so I'll try parse out a few key points and encourage those interested to follow the link to read the document in its entirety.
The WHO has selected nearly 4 dozen H5Nx candidate vaccine viruses (CVVs) for development over the past 20 years. Many of these older CVVs are for viruses that no longer circulate in the wild, having been supplanted by newer versions (see WHO: Candidate Vaccine Viruses for Pandemic Preparedness - Feb 2024).
Although it can be expensive, having a proven CVV already tested and approved can save months of valuable time if mass production and distribution of a pandemic vaccine is ever required.When a new clade, subtype, or variant appears, they check to see if existing CVVs would still be protective. If not, a new CVV would be authorized for development.
Today's report finds that the H5N1 virus infecting cattle in the United States - despite accruing several amino acid changes (L104M, L115Q, T195I, V210A) - has not changed antigenically enough to require a new CVV.
Based on current genetic, antigenic and epidemiologic data, no new CVVs are proposed.
