Sujet : Conditional approval for an H5 vaccine for poultry
De : rokimoto557 (at) *nospam* gmail.com (RonO)
Groupes : talk.originsDate : 17. Feb 2025, 15:37:23
Autres entêtes
Organisation : A noiseless patient Spider
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https://www.science.org/content/article/u-s-conditionally-approves-vaccine-protect-poultry-avian-fluThe vaccine is to a reassorted virus H5N2, but is claimed to have been designed to work against the current H5N1 wild avian virus. Both the B3.13 and the D1.1 genotypes have the H5 gene clade 2.3.4.4b, but their H5 sequences are very different from the H5 sequence that gave the clade it's designation in Asia. By the time the Missouri patient had been infected in October the H5 sequence had changed enough from the B3.13 genotype that the original H5 antigen that came from the first infected dairy worker in Texas was believed to not be effectively neutralized by the antibodies that would be circulating in the Missouri patient, and they made a synthetic H5 antigen sequence with the sequence of the virus isolated from the Missouri patient in order to test for antibodies in their blood. They identified H5 antigens, but 2 of the 3 antibody tests failed for both Missouri cases infected with the dairy virus.
This just means that before this vaccine is used they need to determine if it is effective against the current circulating B3.13 and D1.1 H5N1 virus genotypes. My take is that the current D1.1 genotype is starting to reinfect dairy herds that had already been infected by the B3.13 virus in Nevada, so they likely need a bivalent vaccine that works against both genotypes now infecting poultry flocks and dairy herds.
Ron Okimoto