Is it necessary to vaccinate and revaccinate piglets with a PRRS modified live vaccine? When is the optimal time to do it?
In a geographical area with a high incidence of PRRS. On a stable PRRS-positive farm, what do you think about piglets vaccination with a modified live vaccine (MLV) (negative at birth) at 7 days of age and then again at 3.5 weeks of age?
Vaccination of piglets is designed to try to reduce the problems that may arise from PRRS circulation in the post-weaning or early finishing phase.
The geographical area may influence the risk of introduction of a new variant of PRRS, but in the face of a new introduction, vaccines are not able to effectively contain the damage that this new strain may do.
In fact, this is why they are usually recommended on farms that are already infected. With this characteristic in mind, I would not vaccinate piglets based on that objective alone. However, if piglets are vaccinated with a modified live virus vaccine (MLV), they would only need one dose of vaccine.
The viral replication generated is enough to produce a complete immune response, without the need to revaccinate, which is so important when using inactivated vaccines. In this case I would be more in favor of slightly delaying the administration and vaccinating them at 15 days of life.
If you want to know more about PRRS piglet vaccination read out this previous post: After a recent outbreak, when should piglet vaccination start?
Marcovetgrup S.L. – Spain