Multivalent inactivated virus oil emulsion vaccines in broiler breeder chickens. II. Trivalent vaccines in breeders not previously vaccinated with live Newcastle disease, infectious bursal disease, and tenosynovitis vaccines.

Inactivated Newcastle disease (NDV), infectious bursal disease (IBDV), and viral arthritis/tenosynovitis (VA) viruses were incorporated into water-in-oil emulsion vaccines either alone, in bivalent combinations, or in a trivalent vaccine. Twenty-week-old broiler breeder chickens with no previous exposure to NDV, IBDV, or VA live virus vaccines were injected intramuscularly with the monovalent, bivalent, or trivalent vaccines. The antibody responses to NDV in all three vaccines were poor, and NDV-hemagglutination-inhibition (HI) geometric mean titers (GMTs) never rose above 20 during the 40-week trial. The antibody response to IBDV showed a strong primary response 4 weeks after vaccination, but IBD-VN geometric mean titers declined steadily to less than 100 by 4 months after vaccination. The antibody GMTs to IBDV continued to decline for the remainder of the trial. The antibody response to VA virus was biphasic, with peak VA-virus neutralization (VN) geometric mean titers occurring at 3 months and 6 months postvaccination. The amplitude of the response to the monovalent, bivalent, and trivalent vaccines was inversely proportional to the number of antigens incorporated into each vaccine. Maternal antibody titers in the progeny against each of the three antigens reflected those of the parents. In no case were maternal antibody titers detectable beyond 14 days of age.