Immunogenicity of experimental Streptococcus equisimilis vaccines in swine.
The protective and complement-fixing antibody immune responses to Streptococcus equisimilis vaccines were evaluated in young, surgically derived, colostrum-deprived swine. Comparable levels of protection against live S equisimilis challenge exposure developed in response to sonic-extract, acid-extract, and whole-cell vaccines combined with incomplete Freund adjuvant. The extract vaccines induced higher levels of complement-fixing antibody than did killed, whole cells. Protection, as well as complement-fixing antibody immune responses, were comparable when swine were given doses of vaccine beginning at 3 or 8 weeks of age.
D000818:Animals; D000917:Antibody Formation; D000942:Antigens, Bacterial / Q000302:isolation & purification; D001428:Bacterial Vaccines / Q000302:isolation & purification; D013290:Streptococcal Infections / Q000276:immunology / Q000662:veterinary*; D013291:Streptococcus / Q000276:immunology*; D013552:Swine; D013553:Swine Diseases / Q000276:immunology*; D014611:Vaccination / Q000662:veterinary
D000942:Antigens, Bacterial; D001428:Bacterial Vaccines