Pathogen transmission from vaccinated hosts can cause dose-dependent reduction in virulence.

ABSTRACT: Many livestock and human vaccines are leaky because they block symptoms but do not prevent infection or onward transmission. This leakiness is concerning because it increases vaccination coverage required to prevent disease spread and can promote evolution of increased pathogen virulence. Despite leakiness, vaccination may reduce pathogen load, affecting disease transmission dynamics. However, the impacts on post-transmission disease development and infectiousness in contact individuals are unknown. Here, we use transmission experiments involving Marek disease virus (MDV) in chickens to show that vaccination with a leaky vaccine substantially reduces viral load in both vaccinated individuals and unvaccinated contact individuals they infect. Consequently, contact birds are less likely to de

SUBMITTER: Bailey RI 

PROVIDER: S-EPMC7058279 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature