Broadly neutralizing antibodies to recent, virulent type 2 PRRSV isolates

摘要

Indicators that predict immune protection against PRRS would facilitate herd management and vaccine development programs due to the need for efficacious cross-protection against widely divergent PRRSV isolates. Neutralization of virus infectivity by specific antibodies is a common predictor of immunological efficacy since neutralizing antibodies play a key role in anti-viral immunity in animals and humans. However, their role in protection against PRRS has been discounted since viral neutralization has not been a characteristic and consistent feature of the an-ti-PRRSV immune response. For example, many studies in growing pigs showed that neutralizing antibody responses at weeks to months after infection were frequently absent or present at low titers of 1 /8 or less. Recently, we discovered high titers of broadly neutralizing antibodies in sows from herds with a history of virulent outbreaks or repeated serum inoculation.