H3N2 Component of 2017 Flu Vaccine Only 10% Effective?!

Interesting article from the New England Journal of Medicine about the effectiveness of Australia’s 2017 flu vaccine, and what doctors are seeing in the United States so far.

The investigators determined that circulating influenza A (H3N2) viruses possessed an HA glycosylation site that was lost in the vaccine strain during egg adaptation, and both ferret and human antibodies elicited by that vaccine strain poorly neutralized circulating virus. The researchers also compared antibody responses elicited by vaccine antigens prepared using eggs, cell culture, and the recombinant DNA baculovirus system. They found that most people who mounted a strong antibody response to influenza viruses that contained the HA glycosylation site found on circulating viruses had received the recombinant baculovirus-based vaccine, which was not affected by the egg-adapted mutation.

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