“Immunevasion and recombination are not linked, but both are part of the same complex allowing some PRRS viruses to evade the normal controls on the farm” How can PRRS sometimes manage to penetrate apparently well protected farms? Viral mutation and the relatively slow completion of the pig’s immune response offer clues, according to this conversation with Dr. Enric Mateu, Professor of Animal Health at Universitat Autonoma de Barcelona in Spain and researcher at the CRESA Catalan institute of animal health. Running time: 37 minutes