By Tracey Peake
A new study shows that the effectiveness of current vaccines against porcine reproductive and respiratory syndrome virus (PRRSV) is due to the response of T cells against the disease, rather than the production of antibodies. The work is an important step in identifying specific targets for vaccines on a rapidly mutating virus.
PRRSV is a common and costly disease in pigs that is estimated to cause losses of over $1 billion annually to the pork industry. While current vaccines offer protection, the rapid mutation of PRRSV means that vaccinated pigs cannot produce a consistent or effective broadly neutralizing antibody response.
Antibodies are proteins that “tag” pathogens for destruction by the immune system. T cells are part of the immune system that eliminate infected cells where more viruses are made and help the body remember what those pathogens look like. Vaccines work by stimulating the body to produce antibodies and T cells against the pathogen so that the immune system can identify and destroy it before it gains a foothold and causes clinical disease.