“The antibodies generated by some old vaccine strains have their neutralising capability reduced by the new PPV” Professor André Felipe Streck of the University of Caxias do Sul in Brazil gives his expert view of the key question: Are long-established PPV vaccines still effective when faced with new field strains of the virus? He also discusses whether years of vaccinating sow herds against reproductive failure due to the porcine parvovirus PPV have played any part in the mutation of the virus into newer forms. Running time: 20 minutes