RESUMEN
Aluminium hydroxide-adjuvanted Escherichia coli bacterins were evaluated for efficacy in protecting turkeys against homologous challenge. In each of six trials involving four different E. coli serotypes, poults in one group received a single subcutaneous injection at 1 day of age, poults in a second group were vaccinated twice at 1 and 14 days of age, and those in a third nonvaccinated group served as controls. Vaccinated and control turkeys were challenged at 4 wk of age and survivors were necropsied 1 wk later. Mortality and gross lesion scores of both vaccinated groups were compared with those of the nonvaccinated group. Poults vaccinated twice had significantly lower mortality and less severe gross lesions than poults receiving no vaccine prior to challenge. Immunization with one or two injections of aluminum hydroxide-adjuvanted E. coli bacterin did not impair weight gain of poults.
