Figure 4From: Vaccination of sows against type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) before artificial insemination protects against type 2 PRRSV challenge but does not protect against type 1 PRRSV challenge in late gestationIn situ hybridization for the detection of PRRSV nucleic acid in the thymuses of the litters. The results are the sows that received PRRSV vaccine followed by type 1 PRRSV challenge (group 1, A); sows that received PRRSV vaccine followed by type 2 PRRSV challenge (group 2, B); sows challenged with type 1 PRRSV (group 3, C); sows challenged with type 2 PRRSV (group 4, D).Back to article page