Repeated vaccination against matched H3N2 influenza virus gives less protection than single vaccination in ferrets

Music N, et al. Repeated vaccination against matched H3N2 influenza virus gives less protection than single vaccination in ferrets. NPJ Vaccines. 2019 Jul 9;4:28.
submited by kickingbird at Jul, 19, 2019 18:57 PM from NPJ Vaccines. 2019 Jul 9;4:28.

Epidemiological studies suggest that humans who receive repeated annual immunization with influenza vaccine are less well protected against influenza than those who receive vaccine in the current season only. To better understand potential mechanisms underlying these observations, we vaccinated influenza-naive ferrets either twice, 10 months apart (repeated vaccination group; RV), or once (current season only group; CS), using a prime-boost regimen, and then challenged the ferrets with A/Hong Kong/4801/2014(H3N2). Ferrets that received either vaccine regimen were protected against influenza disease and infection relative to naive unvaccinated ferrets, but the RV group shed more virus, especially at the peak of virus shedding 2 days post infection (p?