Evaluation of the protection of some vaccines used for chickens and ducks against clade 2.3.4.4b A/H5N6 influenza virus isolated in 2016

Abstract

The experiment was performed on chickens and ducks to evaluate the protection of Navetvifluvac and Re-5 vaccines against clade 2.3.4.4b A/H5N6 influenza virus isolated in 2016.
The experimental results showed that Navet-vifluvac vaccine was able to stimulate antibody
response with HI titer of 5.4 log2 in chickens (1 injection) and 8.3 log2 in ducks (2 injections);
meanwhile, chickens had a HI antibody response with a titre of 6.7 log2 and ducks with a titre
of 8.7 log2 when receiving Re-5 vaccination. The virulent challenge by clade 2.3.4.4b A/H5N6
influenza virus showed that Navet-vifluvac vaccine protected 80% of the vaccinated chickens
and 100% of the vaccinated ducks; while the Re-5 vaccine protected 70% of the vaccinated
chickens and 100% of the vaccinated ducks. Both vaccines have the effect of significantly
reducing the amount of virus excreted from the vaccinated chickens and ducks when compared
with animals that was not vaccinated.