Abstract Title
Serological monitoring of avian influenza vaccination in duck flocks, France, 2023-2024
Abstract
The 2.3.4.4.b clade of H5 highly pathogenicity Avian Influenza viruses cause for years large-scale epizootics, substantial economic losses and zoonotic threats, worldwide. Beside biosecurity and culling of infected poultry flocks, vaccination is a supplementary option and is implemented in ducks in France since October, 2023. Such vaccination plan must be associated to an intensive surveillance, including PCR and serology. Based on the use of H5 vaccines, serological testing can be applied for DIVA surveillance (NP ELISA) or for monitoring the immune response to vaccination (H5 ELISA). Here, we performed extensive H5 ELISA profiling of vaccinated duck flocks, including breeders, transmission and decay of maternal antibodies ducklings, meat mule and Muscovy ducks.
Serological monitoring was performed on duck flocks vaccinated with two H5 registered vaccines, either a H5 subunit vaccine or a H5 self-replicative mRNA vaccine. H5 antibodies were titrated using a commercial H5 Duck indirect ELISA or a H5 blocking ELISA kit (IDvet, France). For each flock, 20 birds were bled at different time-points after H5 vaccination. ELISA titers were determined and compared at the individual and flock levels.
ELISA profiles showed a significant seroconversion after the second administration of either vaccine, with significant variations depending on vaccine schedule and duck species. Different booster programs were evaluated in duck breeders. Different matrices for serological testing, including egg yolk, as well as different sample processing protocols were successfully assessed. Altogether, these data confirm the value of serological monitoring to validate the quality of vaccine administration and the accuracy of vaccination programs.
Serological monitoring was performed on duck flocks vaccinated with two H5 registered vaccines, either a H5 subunit vaccine or a H5 self-replicative mRNA vaccine. H5 antibodies were titrated using a commercial H5 Duck indirect ELISA or a H5 blocking ELISA kit (IDvet, France). For each flock, 20 birds were bled at different time-points after H5 vaccination. ELISA titers were determined and compared at the individual and flock levels.
ELISA profiles showed a significant seroconversion after the second administration of either vaccine, with significant variations depending on vaccine schedule and duck species. Different booster programs were evaluated in duck breeders. Different matrices for serological testing, including egg yolk, as well as different sample processing protocols were successfully assessed. Altogether, these data confirm the value of serological monitoring to validate the quality of vaccine administration and the accuracy of vaccination programs.
Co-Author(s)
Jean-Luc GUERIN1, Mathilda WALCH1,2, Clément CASTILLE1, Marina GAIMARD2, Chloé REDAL2, Stéphanie LESCEU2, Sébastien SOUBIES1, Guillaume CROVILLE1
1 IHAP, Université de Toulouse, INRAE, ENVT, 31300 Toulouse, France
2Innovative Diagnostics, 34790 Grabels, France
Abstract Category
Diagnostics, vaccination, or other mitigation strategies for poultry and wildlife