Volume 31, Number 10—October 2025
Research
Effect of Seasonal Influenza Vaccines on Avian Influenza A(H5N1) Clade 2.3.4.4b Virus Infection in Ferrets
Table 1
Serologic response to vaccination in ferrets in study of the effect of seasonal human influenza vaccination on pathogenesis of human influenza A(H5N1) clade 2.3.4.4b virus in the ferret model*
Vaccine group | IAV lineage | Vaccine strain | Prechallenge HAI GMT | Prechallenge ELLA GMT |
---|---|---|---|---|
LAIV | A(H1N1)pdm09 | NO/22 | 806 (606–1074) | 320 (236–434) |
A(H3N2) | TH/22 | 718 (573–901) | 71 (54–95) | |
A(H5N1) | NA | <10 | <10 | |
RIV | A(H1N1)pdm09 | WV/22 | 905 (668–1227) | <10 |
A(H3N2) | MA/22 | 202 (128–317) | <10 | |
A(H5N1) | NA | <10 | <10 | |
IIV3 | A(H1N1)pdm09 | VIC/22 | 45 (30–68) | <10 |
A(H3N2) | TH/22 | <10 | <10 | |
A(H5N1) | NA | <10 | 18.8 (13.0–27.3) | |
MOCK | A(H1N1)pdm09 | NA | <10 | <10 |
A(H3N2) | NA | <10 | <10 | |
A(H5N1) | NA | <10 | <10 |
*Values in parentheses are 95% CIs. n = 6 ferrets per vaccine group, n = 12 ferrets in the mock group. The vaccines contained antigens recommended for the 2024–25 Northern Hemisphere influenza season. ELLA, enzyme-linked lectin assay; GMT, geometric mean titer; HAI, hemagglutination inhibition assay; IAV, influenza A virus; IIV3, Fluarix trivalent inactivated influenza vaccine (GlaxoSmithKline Biologicals, https://www.gsk.com); LAIV, FluMist live attenuated influenza vaccine (AstraZeneca, https://www.astrazeneca.com); MA/22, A/Massachusetts/18/2022 A(H3N2); NA, not available; NO/22, A/Norway/31694/2022 A(H1N1)pdm09; RIV, Flublok vaccine (Sanofi, https://www.sanofi.com); TH/22, A/Thailand/8/2022 A(H3N2); WV/22, A/West Virginia/30/2022 A(H1N1)pdm09; VIC/22, A/Victoria/4897/2022 A(H1N1)pdm09.
1These first authors contributed equally to this article.