Vaccine-Induced Antibody Responses Prevent the Induction of Interferon Type I Responses Upon a Homotypic Live Virus Challenge

During acute viral infections, innate immunity provides essential protective measures to minimize virus dissemination and regulate adaptive immunity. This helps to successfully eliminate the pathogen and establish long-term memory. Here, we investigated the effect of vaccine-induced antibody responses on the induction of IFN-I responses and the associated lymphocyte activation using influenza A virus vaccination and challenge models. Mice were vaccinated with gamma-irradiated influenza A virus (-FLU) and challenged three weeks later with live virus. Our data show a significant reduction in IFN-I responses and lymphocyte activation following a homotypic virus challenge. We confirmed the role of vaccine-induced antibody responses in the observed impairment of IFN-I and the associated lymphocyte activation using adoptive transfer of immune sera and the administration of sera-treated viruses prior to challenge. Overall, we addressed a fundamental concept in immunology and provided experimental data illustrating the inhibition of IFN-I responses in vaccinated animals upon a homotypic virus challenge.