PRRS-MLV vaccination and challenge study work plan.
A Conventional crossbred pigs were randomly divided into six Groups (4 or 5 per Group). PRRS-MLV was administered once without (saline) or with an adjuvant, M. vaccae WCL or CpG ODN, through intramuscular (IM) or intranasal (IN) route. B All the experimental pigs were challenged with a heterologous PRRSV strain 1-4-4 by IN route at 42 dpv. Blood samples were collected and rectal temperature and body weight were recorded at 0, 14, 26, 42 dpv and 3, 7, 10, 14 dpc and pigs were euthanized at 14 dpc.