Stoddart C A, Barlough J E, Baldwin C A, Scott F W
Cornell Feline Health Center, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853-6401.
Res Vet Sci. 1988 Nov;45(3):383-8. doi: 10.1016/S0034-5288(18)30970-6.
Specific pathogen free kittens were vaccinated with an unattenuated field isolate of canine coronavirus (CCV) either by aerosol or subcutaneously, and received boosting vaccinations four weeks later. Aerosolisation elicited a homologous virus-neutralising (VN) antibody response that increased steadily over a four-week period and levelled off one to two weeks after revaccination. The initial aerosolised dose produced an asymptomatic infection with excretion of CCV from the oropharynx up to eight days after vaccination; virus shedding was not detected, however, after the second inoculation. Cats vaccinated subcutaneously developed low VN antibody titres after the first CCV dose and experienced a strong anamnestic response after the second dose. Neutralising antibody titres then levelled off one to two weeks after revaccination at mean values somewhat lower than in cats vaccinated by aerosol. CCV was not isolated from the oropharynx after either subcutaneous dose. Four weeks after CCV boosting inoculations, vaccinated cats and sham-vaccinated control cats were divided into three subgroups and challenged by aerosol with the virulent UCD1 strain of feline infectious peritonitis virus (FIPV UCD1) at three different dosage levels. Five of six cats (including sham-vaccinated controls) given the lowest challenge dose showed no signs of disease, while all other cats developed lesions typical of feline infectious peritonitis (FIP). The five surviving cats developed FIP after subsequent challenge with a fivefold higher dose of FIPV. Thus heterotypic vaccination of cats with CCV did not provide effective protection against FIPV challenge.
将无特定病原体的小猫通过气溶胶或皮下注射方式接种犬冠状病毒（CCV）的非减毒野外分离株，并在四周后进行加强免疫。气溶胶接种引发了同源病毒中和（VN）抗体反应，该反应在四周内稳步增加，并在再次接种后一到两周趋于平稳。初始气溶胶剂量导致无症状感染，接种疫苗后长达八天从口咽部排出CCV；然而，第二次接种后未检测到病毒脱落。皮下接种的猫在首次接种CCV后产生低VN抗体滴度，并在第二次接种后出现强烈的回忆反应。中和抗体滴度在再次接种后一到两周趋于平稳，平均值略低于通过气溶胶接种的猫。皮下接种后，口咽部均未分离到CCV。CCV加强免疫接种四周后，将接种疫苗的猫和假接种对照猫分为三个亚组，并以三种不同剂量水平通过气溶胶用猫传染性腹膜炎病毒（FIPV UCD1）的强毒株UCD1进行攻毒。接受最低攻毒剂量的六只猫中有五只（包括假接种对照）未出现疾病迹象，而所有其他猫都出现了典型的猫传染性腹膜炎（FIP）病变。五只存活的猫在随后用五倍高剂量的FIPV攻毒后发生了FIP。因此，用CCV对猫进行异型疫苗接种不能有效保护其免受FIPV攻毒。
