The next flu vaccine

https://www.cidrap.umn.edu/influenza-vaccines/fda-cancels-advisory-committee-meeting-flu-vaccine-strain-selection
The FDA cancelled their schedulted meeting on flu vaccine strain selection.
https://www.cidrap.umn.edu/influenza-vaccines/who-advisers-swap-out-h3n2-strains-next-northern-hemisphere-flu-vaccines
WHO is thinking of changing the H3N2 strain, but an article that I recall seeing claimed that it was the H1N1 vaccine strain that was not closely enough related to the H1N1 strain causing the most damage in the field.  They got lucky this year and selected an H3N2 and an H1N1 vaccine strain, and the two most common infections split about 50-50 is H3N2 and H1N1, but the vaccine apparently isn't doing as well against H1N1 infections.
The antigen designations for the HA and NA genes are probably 30 or 40 years old.  They may still call it H5, but the Dairy virus has a specific clade designation, and the current clade was identified in 2009, so the current H5 sequence is very different from the original clade ancestor.  H5 has existed since the 1980's, as far as I can tell, so they go by clade designation for H5 genotypes, and even some of the clade designations are getting pretty old.  The dairy B3.13 genotype and the D1.1 genotype have an H5 gene of the same Asian clade, but even though they are both designated H5N1 the N1 gene of the D1.1 variant comes from a North American avian influenza strain, so it is not closely related to the N1 gene found in the B3.13 genotype.  It should be noted that the H5N1 avian influenza started infecting humans back in 1997 in Asia.  The H5 gene has changed quite a bit since then, but they still call it H5N1.  As far as I know they still have not tested the D1.1 H5N1 genotype against the H5N1 vaccine that they stockpiled.  The original dairy virus was neutralized by antibodies produced by the vaccine strain, but the sequence has changed a lot since the first infections, and my guess is that the vaccine would not have been effective against the virus that infected the Missouri patient.
When they pick vaccines they have to take these things into account, and WHO wants to change the H3N2 variant, but right now we could be doing better if we had an H1N1 virus more closely related to the field strains infecting a lot of people.  Probably both vaccine strains need to be replaced with ones closer to the current field isolates.
Ron Okimoto