The B cell response to foot-and-mouth disease virus in cattle following vaccination and live-virus challenge

Antibodies play a pivotal role against viral infection, and maintenance of protection is dependent on plasma and memory B cells. Understanding antigen-specific B cell responses in cattle is essential to inform future vaccine design. We have previously defined T cell-dependent and -independent B cell responses in cattle, as a prelude to investigating FMDV-specific B cell responses. In this study we have used a FMDV O-serotype vaccination (O1 Manisa or O SKR) and live virus challenge (FMDV O SKR) to investigate the homologous and heterologous B cell response in cattle following both vaccination and live virus challenge. The FMDV O-serotype vaccines were able to induce a cross reactive plasma cell response, specific for both O1-Manisa and O SKR, post-vaccination. Post FMDV O SKR live-virus challenge the heterologous O1-Manisa vaccination provided cross-protection against O SKR challenge and cross-reactive O SKR-specific plasma cells were induced. However, vaccination and live-virus challenge were not able to induce a detectable FMDV O-serotype-specific memory B cell response in any of the cattle. The aim of new FMDV vaccines should be to induce memory responses and increased duration of immunity in cattle.