If you are producing PRRSV negative piglets at weaning from PRRS vaccinated sow herd but they are transferred to a PRRS positive finishing site (with PRRS related respiratory symptoms) at 40kgs, would it be sensible to vaccinate these piglets at weaning?
Based on Lars Erik Larsen opinion, there are two different options to approach this situation:
1. Vaccinate the pigs at weaning, prior to shipment
A lot of Danish herds are selling piglets to Germany and other countries and several of these pigs are vaccinated prior to shipment so vaccination at weaning is indeed a feasible solution.
However, some of the pigs may remain viraemic so there is a risk that they may transfer the virus on to the finisher site, but if this herd is PRRSV positive anyway this will not be a problem.
2. Vaccinate the pigs at arrival to the finisher site
We have also tried another solution in a single herd where we vaccinated the pigs at arrival at the finisher site followed by strict sectioning.
We did that until all the sections contained vaccinated pigs and then stopped vaccinating incoming pigs.
Using this approach, we pushed the circulating field strain out of the finisher site, however, the vaccine strain persisted in the herd – but without causing any impact on production nor health.
Find here useful information about a field experience in Korea where piglets were vaccinated with UNISTRAIN® PRRS before transport to multiorigin fattening farms to reduce the mortality rate.
National Veterinary Institute of Denmark