Chickens from one day old (breeders and layers).

Active immunization of chickens to reduce colonization, persistence and invasion of the intestinal tract and internal organs by Salmonella Enteritidis. Onset of immunity within 6 days after first vaccination. The duration of immunity after two step vaccination is demonstrated 35 weeks after second vaccination according to the recommended programme. The duration of immunity after the three step vaccination is demonstrated 63 weeks after third vaccination according to the recommended programme.