Wageningen University has recently published on evaluation of two live vectored vaccines to provide protection against H5 avian influenza. The studies were sponsored by the Ministry of Agriculture, Fisheries, Food Security and Nature of the Netherlands, after laboratory evaluation showed efficacy and safety.
The field trial comprised two farms each holding 1,800 hens. The trial compared Vectormune® AI or Vaxxitek® HVT+IBD+H5 against non-vaccinated controls. Chicks were vaccinated in September 2023 and the longitudinal study will continue through early 2025.
Day-old chicks received either of the vaccines by injection at day of hatch with some pullets receiving an additional booster vaccination at 12 weeks of age. Irrespective of vaccine applied, at 8 weeks of age, all pullets were protected against challenge with a circulating field strain of H5N1 HPAI under controlled laboratory conditions. A second challenge was conducted at 24 weeks of age.. Hens receiving either of the vaccines at day-old showed 10 percent mortality on challenge. Hens receiving both the day-old vaccine and in addition the 12-week booster were clinically unaffected and all survived challenge. Viral shedding following challenge was sharply decreased in the vaccinated treatments. Non-vaccinated controls showed 100 percent mortality.
Bouwman, K.M. et al Progress report: Transmission study testing HVT-based H5 vaccine against highly pathogenic avian influenza (HPAI) H5N1 virus (clade 2.3.4.4b). Wageningen Bioveterinary Research Publications September 2024 doi: 10.18174/669647