Haesebrouck F, Pensaert M, Wyffels R
Vet Q. 1987 Jan;9(1):9-14. doi: 10.1080/01652176.1987.9694071.
Intratracheal inoculation of 2 Belgian H3N2-influenza viral strains, isolated from sick swine in the field, caused high fever, anorexia and dyspnoea in unvaccinated swine. The strains are related to the human A/Port Chalmers/1/73 (H3N2)-strain. In a limited study, 2 subunit vaccines, both derived from the human A/Philippines/2/82 (H3N2)-strain, were tested for efficacy in protecting swine against these Belgian field isolates. Vaccine A was a commercial vaccine, vaccine B an experimental vaccine. For evaluation of the efficacy of the vaccines, clinical as well as virological parameters were used. It was found that 2 spaced injections of the experimental vaccine (B) resulted in very high serum hemagglutination-inhibition (HI) titres against the Philippines-strain. Nevertheless, only partial protection was obtained, as indicated by the milder clinical signs and the decreased viral replication at challenge. One injection of the experimental vaccine (B) and 2 spaced injections of the commercial vaccine (A) did not result in any protection at challenge, even though moderate HI titres against the Philippines-strain were obtained. It was concluded that if an H3N2-strain is included in vaccines for use in swine, a strain should be selected which is identical or very closely related to the strain(s) prevalent in the swine population of the country in which the vaccine will be used.
用从患病猪中分离出的2株比利时H3N2流感病毒株进行气管内接种，可使未接种疫苗的猪出现高热、厌食和呼吸困难。这些毒株与人类A/查尔姆斯港/1/73（H3N2）毒株相关。在一项有限的研究中，对两种均源自人类A/菲律宾/2/82（H3N2）毒株的亚单位疫苗进行了测试，以评估其在保护猪免受这些比利时田间分离株感染方面的效果。疫苗A是一种商业疫苗，疫苗B是一种实验性疫苗。为了评估疫苗的效果，使用了临床和病毒学参数。结果发现，间隔注射2次实验性疫苗（B）可产生针对菲律宾毒株的非常高的血清血凝抑制（HI）效价。然而，如在攻毒时临床症状较轻和病毒复制减少所示，仅获得了部分保护。注射1次实验性疫苗（B）和间隔注射2次商业疫苗（A）在攻毒时未产生任何保护作用，尽管获得了针对菲律宾毒株的中等HI效价。得出的结论是，如果猪用疫苗中包含H3N2毒株，则应选择与疫苗使用国猪群中流行的毒株相同或密切相关的毒株。
