Central Veterinary Institute of Wageningen UR (CVI), Virology Department, P.O. Box 65, 8200 AB Lelystad, The Netherlands.
Vet Microbiol. 2011 Sep 28;152(3-4):304-14. doi: 10.1016/j.vetmic.2011.05.027. Epub 2011 May 24.
In April 2009 a new influenza A/H1N1 strain, currently named "pandemic (H1N1) influenza 2009" (H1N1v), started the first official pandemic in humans since 1968. Several incursions of this virus in pig herds have also been reported from all over the world. Vaccination of pigs may be an option to reduce exposure of human contacts with infected pigs, thereby preventing cross-species transfer, but also to protect pigs themselves, should this virus cause damage in the pig population. Three swine influenza vaccines, two of them commercially available and one experimental, were therefore tested and compared for their efficacy against an H1N1v challenge. One of the commercial vaccines is based on an American classical H1N1 influenza strain, the other is based on a European avian H1N1 influenza strain. The experimental vaccine is based on reassortant virus NYMC X179A (containing the hemagglutinin (HA) and neuraminidase (NA) genes of A/California/7/2009 (H1N1v) and the internal genes of A/Puerto Rico/8/34 (H1N1)). Excretion of infectious virus was reduced by 0.5-3 log(10) by the commercial vaccines, depending on vaccine and sample type. Both vaccines were able to reduce virus replication especially in the lower respiratory tract, with less pathological lesions in vaccinated and subsequently challenged pigs than in unvaccinated controls. In pigs vaccinated with the experimental vaccine, excretion levels of infectious virus in nasal and oropharyngeal swabs, were at or below 1 log(10)TCID(50) per swab and lasted for only 1 or 2 days. An inactivated vaccine containing the HA and NA of an H1N1v is able to protect pigs from an infection with H1N1v, whereas swine influenza vaccines that are currently available are of limited efficaciousness. Whether vaccination of pigs against H1N1v will become opportune remains to be seen and will depend on future evolution of this strain in the pig population. Close monitoring of the pig population, focussing on presence and evolution of influenza strains on a cross-border level would therefore be advisable.
2009 年 4 月，一种新型甲型 H1N1 流感病毒，目前被命名为“大流行（H1N1）流感 2009”（H1N1v），引发了自 1968 年以来的首次人类大流行。世界各地也有报告称，这种病毒多次入侵猪群。给猪接种疫苗可能是减少人类接触感染猪的一种选择，从而防止跨物种传播，但也可以保护猪本身，如果这种病毒对猪群造成损害。因此，测试并比较了三种猪流感疫苗，其中两种是商业疫苗，一种是实验疫苗，以评估它们对 H1N1v 挑战的疗效。一种商业疫苗基于美国经典 H1N1 流感株，另一种基于欧洲禽流感 H1N1 流感株。实验疫苗基于重配病毒 NYMC X179A（含有 A/California/7/2009（H1N1v）的血凝素（HA）和神经氨酸酶（NA）基因以及 A/Puerto Rico/8/34（H1N1）的内部基因）。根据疫苗和样本类型的不同，两种商业疫苗均可减少 0.5-3 个对数（10）的病毒排泄。两种疫苗均能减少病毒复制，特别是在下呼吸道，接种疫苗并随后受到挑战的猪的病理损伤比未接种疫苗的对照组少。用实验疫苗接种的猪，鼻拭子和咽拭子中传染性病毒的排泄水平达到或低于 1 个对数（10）TCID（50）/拭子，且仅持续 1 或 2 天。含有 H1N1v 的 HA 和 NA 的灭活疫苗能够保护猪免受 H1N1v 感染，而目前可用的猪流感疫苗效果有限。是否给猪接种 H1N1v 疫苗将成为一个机会，这还有待观察，这将取决于这种病毒在猪群中的未来演变。因此，密切监测猪群，重点关注跨境流感株的存在和演变是明智的。
