Modified-live PRRSV subtype 1 vaccine UNISTRAIN ® PRRS provides a partial clinical and virological protection upon challenge with East European subtype 3 PRRSV strain Lena

Background Western European porcine reproductive and respiratory syndrome virus (PRRSV) strains cause limited and mild clinical signs whereas more virulent strains are circulating in Eastern Europe. The emergence of such highly virulent strains in Western Europe might result in severe clinical problems and a financial disaster. In this context, the efficacy of the commercial modified-live PRRSV subtype 1 vaccine UNISTRAIN® PRRS was tested upon challenge with the East European subtype 3 PRRSV strain Lena.