Unravelling the role of non-responding piglets and sows to vaccination against PRRSV: prevalence, risk factors and possible consequences

Korte beschrijving

Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) is one of the most important pathogens in pig farms worldwide, as it is responsible for enormous production and economic losses. PRRSV infection in gestating gilts and sows induces reproductive failure, with an increased incidence of irregular return to estrus, abortions, and the birth of weak, premature, or dead piglets. Additionally, respiratory distress (coughing, sneezing, and dyspnea) is observed in infected piglets and growing pigs, resulting in growth retardation and increased mortality. Importantly, PRRSV infection is correlated with a reduction in respiratory immunity, making PRRSV-infected pigs more susceptible to opportunistic, secondary pathogens. Despite the availability of commercial PRRSV vaccines for more than three decades, control of the disease remains a frustrating and challenging task for herd owners worldwide. This thesis was initiated based on field reports stating the presence of piglets and sows that test PRRSV seronegative, despite PRRSV vaccination being practiced: the so-called non-responders to vaccination.