Safety, efficacy, and duration of immunity of a PRRSv MLV vaccine in 1 day-of-age pigs

摘要

In studies with 1 day-of-age pigs, an experimental Porcine Reproductive &: Respiratory Syndrome modified-live virus (MLV) vaccine demonstrated safety, efficacy, and duration of immunity.An initial 1 day-of-age safety and efficacy study was performed. Pigs were vaccinated at 1 day-of-age (n = 11) and controls (n = 7) received a placebo. No biologically relevant differences in clinical observations were observed among vaccinates over controls during the vaccination phase. Pigs were challenged at 7 weeks of age with a heterologous PRRSv isolate NADC20 and were necropsied 10 days post-challenge. Vaccination demonstrated a 90% reduction in lung lesions (controls 33.0% vs. vaccinates 3.3%, P< 0.0001).