Efficacy of equine influenza vaccines for protection against A/Equine/Jilin/89 (H3N8)--a new equine influenza virus.
Efficacy of equine influenza vaccines for protection against A/Equine/Jilin/89 (H3N8)--a new equine influenza virus.
复制标题
马流感疫苗对预防新型马流感病毒 A/Equine/Jilin/89 (H3N8) 的功效。
DOI：
10.1016/0264-410x(93)90122-e
复制
发表时间：
1993
期刊：
影响因子：
5.5
通讯作者：
Thomas,TL
中科院分区：
文献类型：
--
作者：
Webster,RG;Thomas,TL
1989年东北地区出现了一种新型H3N8马流感病毒[A/ equine /吉林市/1/89 （Eq/吉林市）]，造成了马的高死亡率；现有证据表明，它尚未在世界本区域以外蔓延。对感染后雪貂血清进行血凝抑制（HI）试验的血清学分析证实Eq/吉林型与1963年至1991年分离的H3N8型马流感病毒具有抗原性差异，同时也表明当前的马流感病毒[a/ equine /Alaska/1/91 (H3N8)]经历了抗原漂移。在本研究中，我们确定针对血凝素含量标准化的最新H3N8流感病毒[a /Equine/Kentucky/1277/90 (Eq/Kentucky)]的疫苗是否能保护小鼠免受来自中国的新型H3N8流感病毒的致命攻击。完全保护的定义是攻击后3天在小鼠肺部阻止病毒复制。高剂量Eq/Kentucky水悬液疫苗（每剂量0.5-5.0 μ HA）对接种动物肺部病毒滴度的影响最小。佐剂中的Eq/Kentucky疫苗（每剂量1.0 ~ 5.0 μ HA）对Eq/吉林小鼠的攻毒具有完全的保护作用。在0.5 ~ 5 μg HA和0.1 ~ 5.0 μg HA的佐剂剂量范围内，Eq/吉林水悬液疫苗对小鼠具有完全的保护作用。水悬液中每剂量0.5 ~ 5.0 μg的HA和佐剂中每剂量0.01 ~ 5.0 μg的HA均可诱导对Eq/吉林型和Eq/Kentucky型的同源保护。低剂量疫苗（0.01 ~ 0.1 μg HA）不能诱导出可检测的HI抗体，但仍能保护小鼠；ELISA和中和抗体与保护相关。研究表明，市售马流感疫苗与Eq/吉林病毒的交叉保护作用很小，但确实可以预防死亡。目前的研究表明，来自中国的新型H3N8马流感病毒与目前流行的H3N8马流感病毒可以用疫苗诱导交叉保护，但需要高剂量的疫苗；市售疫苗不含足够的抗原，无法对小鼠产生完全的保护作用。
A new H3N8 equine influenza virus [A/Equine/Jilin/1/89 (Eq/Jilin)] appeared in Northeastern China in 1989 and caused high mortality in horses; the available evidence indicates that it has not yet spread outside this region of the world. Serological analysis with postinfection ferret sera in haemagglutination inhibition (HI) tests confirmed that Eq/Jilin is antigenically distinct from H3N8 equine influenza viruses isolated between 1963 and 1991 and also showed that a current equine influenza virus [A/Equine/Alaska/1/91 (H3N8)] had undergone antigenic drift. In the present study we determine if vaccine against a recent H3N8 influenza virus [A/Equine/Kentucky/1277/90 (Eq/Kentucky)] that was standardized for haemagglutinin content will protect mice against lethal challenge with the new H3N8 influenza virus from China. Complete protection is defined as prevention of virus replication in the lungs of mice 3 days after challenge. High doses of Eq/Kentucky vaccine in aqueous suspension (0.5–5.0 μg HA per dose) provided minimal protection against Eq/Jilin challenge as judged by virus titres in the lungs of vaccinated animals. Eq/Kentucky vaccine in adjuvant (1.0–5.0 μg HA per dose) did provide complete protection against challenge with Eq/Jilin in mice. Eq/Jilin vaccine in aqueous suspension induced complete protection of mice against challenge with Eq/Kentucky at doses from 0.5 to 5 μg HA and in adjuvant doses of Eq/Jilin from 0.1–5.0 μg HA were efficacious. Homologous protection against Eq/Jilin or Eq/Kentucky was induced by doses of vaccine from 0.5–5.0 μg HA per dose in aqueous suspension and from 0.01–5.0 μg HA per dose in adjuvant. Lower doses of vaccine (0.01–0.1 μg HA) failed to induce detectable HI antibodies yet the mice were protected; ELISA and neutralizing antibodies correlated with protection. Studies showed that commercially available equine influeza vaccines provided minimal cross-protection with Eq/Jilin virus but did prevent mortality. The present studies indicate that cross-protection can be induced against the new H3N8 equine influenza virus from China with vaccine to the currently circulating equine H3N8 viruses but high doses of vaccine are needed; commercially available vaccines do not contain sufficient antigen to induce complete protection in mice.