Comparison of avian influenza virus contamination in the environment before and after massive poultry H5/H7 vaccination in Zhejiang province, China

Background Information regarding comparison of the environmental prevalence of avian influenza virus (AIVs), before and after massive poultry vaccinations, is limited. Our study aimed to detect differences in the prevalence of AIVs type A and subtypes H5, H7, and H9 before and after the September 2017 massive poultry vaccination, across different sampling places and types.