Central Veterinary Institute of Wageningen UR (CVI), Virology Department, P.O. Box 65, 8200AB Lelystad, The Netherlands.
Vaccine. 2011 Feb 11;29(8):1545-50. doi: 10.1016/j.vaccine.2010.12.096. Epub 2011 Jan 8.
In 2009 a new influenza A/H1N1 virus strain ("pandemic (H1N1) 2009", H1N1v) emerged that rapidly spread around the world. The virus is suspected to have originated in swine through reassortment and to have subsequently crossed the species-barrier towards humans. Several cases of reintroduction into pigs have since been reported, which could possibly create a reservoir for human exposure or ultimately become endemic in the pig population with similar clinical disease problems as current swine influenza strains. A soluble trimer of hemagglutinin (HA), derived from the H1N1v, was used as a vaccine in pigs to investigate the extent to which this vaccine would be able to protect pigs against infection with the H1N1v influenza strain, especially with respect to reducing virus replication and excretion. In a group of unvaccinated control pigs, no clinical symptoms were observed, but (histo)pathological changes consistent with an influenza infection were found on days 1 and 3 after inoculation. Live virus was isolated from the upper and lower respiratory tract, with titres up to 10(6) TCID(50) per gram of tissue. Furthermore, live virus was detected in brain samples. Control pigs were shedding live virus for up to 6 days after infection, with titres of up to 10(5) TCID(50) per nasal or oropharyngeal swab. The soluble H1N1v HA trimer diminished virus replication and excretion after a double vaccination and subsequent challenge. Live virus could not be detected in any of the samples taken from the vaccinated pigs. Vaccines based on soluble HA trimers provide an attractive alternative to the current inactivated vaccines.
2009 年，一种新的甲型 H1N1 流感病毒株（“大流行（H1N1）2009”，H1N1v）迅速在全球范围内传播。该病毒疑似起源于猪，通过基因重配而产生，并随后跨越物种屏障传播至人类。此后，有几例猪再次感染的报告，这可能会为人类暴露创造一个储层，或者最终导致猪群中出现类似于当前猪流感株的地方性疾病问题。一种源自 H1N1v 的可溶性血凝素（HA）三聚体被用作猪的疫苗，以研究该疫苗在多大程度上能够保护猪免受 H1N1v 流感株的感染，特别是在减少病毒复制和排泄方面。在一组未接种疫苗的对照猪中，未观察到临床症状，但在接种后第 1 天和第 3 天发现了与流感感染一致的（组织）病理学变化。从上呼吸道和下呼吸道分离到活病毒，组织滴度高达每克组织 10(6)TCID(50)。此外，在脑组织样本中也检测到活病毒。对照猪在感染后长达 6 天内持续排出活病毒，鼻拭子或咽拭子的滴度高达 10(5)TCID(50)。在两次接种和随后的攻毒后，可溶性 H1N1v HA 三聚体可减少病毒复制和排泄。从接种疫苗的猪身上采集的任何样本中均未检测到活病毒。基于可溶性 HA 三聚体的疫苗为当前的灭活疫苗提供了一种有吸引力的替代方案。
