Eradication of Aujeszky's disease in North Rhine Westphalia: Comparison ofvaccination regimes for piglets based on their ability to induce humoral antibodies in the presence of maternal immunity

Five different vaccination regimes with attenuated Aujeszky g1(-)-vaccine, including an intranasal vaccine administered at five weeks of age, were com pared for their ability to induce humoral antibodies in the presence of mat ernal immunity. A continuous decline in detectable antibodies in all 36 pig lets following vaccination at five weeks of age demonstrated the strong inf luence of passive antibodies. Following the administration of a booster vac cination intramuscularly the immunity induced increased some 46 time in ani mal with low concentrations of maternal antibodies while it increased some 3.6 times in animals with high concentrations of maternal antibodies. Howev er 94% of the animals vaccinated intranasally at an age o five weeks exhibi ted humoral antibody titres greater than 1:40 at the end of the trial compa red to only 9% of the piglets vaccinated conventionally.