The betterment of PRRSV vaccines is a national priority for the swine industry and for USDA as well. National Pork Board’s Swine Research Program and also USDA-AFRI-NIFA research program assign top priority to the development of cross protective strategies for PRRS immunization, which should result in the enhancement of a vaccine’s ability to provide heterologous protection (i.e. protection against PRRSV Strains that are distant or very different from the strain used for vaccination). Such fundamental requirement for improving current vaccines is dictated by the formidable genetic diversity of the multiple strains of PRRSV that simultaneously circulate in the field.

In our laboratories we explore two major alternatives towards the pursuit of broadly protective PRRSV vaccines:
1) The development of consensus-sequence live vaccines that would improve heterologous protection founded on major conserved determinants of protection (epitopes) inducing (T) cell-mediated immunity, and
2) Discovery of key antigenic determinants of protection (conserved B-cell epitopes) that enter in the composition of external glycoproteins of PRRSV that would induce the development of broadly neutralizing antibodies capable of preventing infection by many diverse heterologous PRRSV strains.

This NPB report pertains to experiments on this second category, with results that would directly lead to the development of more effective PRRSV subunit (non-replicating) vaccines for broad protection. The initial results of the NPB project herein reported, have been the basis for our being awarded a substantially higher USDA-NIFA-AFRI award that should direct us, by 2016, to the characterization of the key determinants (B cell epitopes) of protection giving origin to broadly neutralizing antibodies against PRRSV. The existence of such broadly-neutralizing antibodies have been inferred through several different research reports but so far no broadly-neutralizing antibody has been categorically discovered. Such is our proposed target to be achieved in 2016.