Maternally Derived Antibodies: Background, function and importance

‘Maternally Derived Antibodies’ (MDA) is a term which appears in more than one immunological context. These antibodies are induced by both the exposure to natural disease and by the active immunisation of gilts or sows, and can confer passive immunity to newborn piglets. But in doing so, they are also capable of interfering with the piglets’ own immune response to vaccines. By Alex A.S. Eggen DVM, Intervet/Schering-Plough Animal Health, Boxmeer, the Netherlands Maternally Deri