Commentary
Human H7N2 Reassortant Sequences Withdrawn from Genbank
Recombinomics Commentary 06:18
May 28, 2008
Here, we use glycan microarray technology to determine the receptor-binding preference of H7 influenza viruses of both Eurasian and North American lineages and assess the transmissibility of selected H7 influenza viruses using the ferret model. Surprisingly, we found that recently isolated H7N2 and H7N3 viruses of the North American lineage possess increased binding to 2–6 SA, with several strains exhibiting preferential binding characteristic of human influenza viruses. One of these was an H7N2 virus, A/NY/107/03, associated with respiratory disease in an adult male, which we found to be capable of efficient direct contact transmission in the ferret model.
The above comments describe increased affinity of North American H7 isolates for “human” receptors, as described in this week’s PNAS paper. The one isolate that has been efficiently transmitted in a ferret model has been discussed previously.
The isolate is from a patient in New York who was diagnosed March 17, 2003 after presenting in November, 2002. Sequences for seven of the eight gene segments were deposited at Genbank on March 24, 2008, 3 days after the PNAS paper was accepted for publication. The deposited sequences represented a clear human / avian reassortant. Three genes (HA, NA, NP) were avian and from a North American H7N2 source. The other four genes (PB1, PA, MP, NS) were clearly human, most closely related to H3N2 isolates from New York, circa 2003.
The sequences were accessible at the end of last month, but have since been withdrawn.
More information on why these sequences were withdrawn, and the status of the sequences, including PB2 which was not released earlier, would be useful.
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