Vaccination studies of aspergillosis in turkeys: subcutaneous inoculation with several vaccine preparations followed by aerosol challenge exposure.
Five vaccines were prepared from an isolate of Aspergillus fumigatus: a culture filtrate vaccine (I), a spore vaccine (II), a mycelial vaccine (III), and 2 germling vaccines (IV and V). The 2 germling vaccines were produced on different media. Two experiments were conducted to test the vaccines for efficacy in groups of 21 turkey poults by giving each bird 2 subcutaneous inoculations of the respective vaccine at 1 and 2 weeks of age. The birds were challenge exposed to an aerosol of spores of A fumigatus at 1 month of age. The 2 experiments differed only in the challenge exposure. In experiment 1, 38% of the poults were protected when vaccinated with an A fumigatus germling vaccine (IV) and challenge exposed with a dose of aerosolized A fumigatus spores that killed 100% of the nonvaccinated controls. Onset of postchallenge-exposure deaths were delayed by 2 days in the turkeys given vaccine IV. In experiment 2, 48% of the poults were protected when given germling vaccine IV, whereas 62% to 86% of the poults in the nonvaccinated and 3 other vaccine groups died. In experiment 2, 50% of the poults given a mycelial vaccine (III) were protected. Torticollis was a frequent sign of the disease in experiment 2.