Terpstra C, Wensvoort G
Central Veterinary Institute, Virology Department, Lelystad, The Netherlands.
Vet Microbiol. 1988 Feb;16(2):123-8. doi: 10.1016/0378-1135(88)90036-3.
The relationship between vaccine-induced antibody titres against swine fever virus (SFV), as measured by the neutralisation peroxidase-linked assay (NPLA), and protection against virus multiplication, excretion and transmission, disease and death was studied in 46 pigs. The pigs were housed individually and challenged intranasally with 100 pig ID50 of the virulent Brescia strain of SFV. In order to detect virus transmission, a swine fever (SF)-susceptible sentinel pig was placed in contact with the vaccinated animal 2 days after challenge. All 11 pigs with pre-challenge NPLA titres less than 12.5 responded to the challenge with fever, 8 out of 10 showed leucopenia, 7 transmitted virus to their contact and 3 died. Of the 9 animals with titres greater than or equal to 12.5 and less than 25, 8 developed fever, 6 out of 7 had leucopenia, 2 excreted and/or transmitted virus and all survived. Of the 12 pigs with pre-challenge titres greater than or equal to 25 and less than 50, 5 responded with fever, 6 out of 10 had leucopenia, 4 excreted virus and none died. Although all pigs with prechallenge titres greater than or equal to 50 showed a booster response, virus transmission was not observed, indicating that in the case of exposure such animals would not contribute towards the spread of field virus. From an epidemiological point of view, titres less than 32 were found inadequate.
通过中和过氧化物酶联试验（NPLA）测定的针对猪瘟病毒（SFV）的疫苗诱导抗体滴度，与46头猪抵抗病毒增殖、排泄、传播、疾病和死亡之间的关系进行了研究。这些猪单独饲养，并经鼻用100个猪感染剂量50（ID50）的强毒布雷西亚株SFV进行攻毒。为了检测病毒传播，在攻毒后2天将一头对猪瘟（SF）易感的哨兵猪与接种疫苗的动物接触。攻毒前NPLA滴度小于12.5的所有11头猪对攻毒有发热反应，10头中有8头出现白细胞减少，7头将病毒传播给其接触的猪，3头死亡。在滴度大于或等于12.5且小于25的9头动物中，8头发热，7头中有6头白细胞减少，2头排泄和/或传播病毒，全部存活。在攻毒前滴度大于或等于25且小于50的12头猪中，5头发热，10头中有6头白细胞减少，4头排泄病毒，无死亡。尽管攻毒前滴度大于或等于50的所有猪均显示有增强反应，但未观察到病毒传播，这表明在暴露情况下，此类动物不会促进田间病毒的传播。从流行病学角度来看，发现滴度小于32是不够的。
