据新华社电 一个国际研究团队18日在美国西雅图举行的疟疾论坛上宣布，初步临床试验结果显示，一种名为RTS，S的疫苗可以显著降低儿童患疟疾的风险。这项研究成果同日发表在美国《新英格兰医学杂志》上。
美国疾病控制和预防中心专门发表声明对RTS，S疫苗研究取得重大进展表示欢迎，并称这一疫苗如研制成功，将挽救成千上万的生命，向实现疟疾零死亡目标又走近一步。
RTS，S疫苗已由英国葛兰素史克公司研发了25年，在美国比尔和梅林达·盖茨基金会的资助下，疫苗的三期临床试验将持续到2014年，试验对象为撒哈拉以南7个非洲国家11个研究点的超过1.5万名儿童。而初步结果显示，在为期12个月的观察期内，6000名5个月至17个月幼儿注射3剂疫苗后，患疟疾和恶性疟疾的风险分别降低了56%和47%。
“这些结果令人鼓舞，但我们还有很长的路要走，”领导加纳一所医院临床试验的特希里·阿贝耶加当天在论坛上宣布研究结果时如是表示。
葛兰素史克公司首席执行官安德鲁·威蒂在论坛上说，大部分疫苗有效率达到90%以上才开始上市，因此47%的有效率显得不是很高，但即便这样的有效率也能在10年内挽救数百万人的生命。
威蒂表示，葛兰素史克已在这一疫苗上投入3亿多美元，预计将继续投入1亿美元，如果被批准上市，疫苗很可能被命名为Mosquirix，售价为成本加5%的利润，其中的利润部分将继续用于疟疾研究。
疟疾是由疟原虫引起的疾病，通过蚊子叮咬传播，其症状包括发热、头痛、呕吐等，如不及时治疗可能危及生命。据统计，全球每年约有80万人死于疟疾，非洲大约每30秒就有一个幼儿因疟疾而死亡。长期以来，医学界一直致力于疟疾疫苗开发，但进展总体缓慢，其难度远远超过病毒疫苗。(生物谷 Bioon.com)
doi:10.1056/NEJMoa1102287
PMC:
PMID:
First Results of Phase 3 Trial of RTS,S/AS01 Malaria Vaccine in African Children
The RTS,S Clinical Trials Partnership
Background
An ongoing phase 3 study of the efficacy, safety, and immunogenicity of candidate malaria vaccine RTS,S/AS01 is being conducted in seven African countries.
Methods
From March 2009 through January 2011, we enrolled 15,460 children in two age categories — 6 to 12 weeks of age and 5 to 17 months of age — for vaccination with either RTS,S/AS01 or a non-malaria comparator vaccine. The primary end point of the analysis was vaccine efficacy against clinical malaria during the 12 months after vaccination in the first 6000 children 5 to 17 months of age at enrollment who received all three doses of vaccine according to protocol. After 250 children had an episode of severe malaria, we evaluated vaccine efficacy against severe malaria in both age categories.
Results
In the 14 months after the first dose of vaccine, the incidence of first episodes of clinical malaria in the first 6000 children in the older age category was 0.32 episodes per person-year in the RTS,S/AS01 group and 0.55 episodes per person-year in the control group, for an efficacy of 50.4% (95% confidence interval [CI], 45.8 to 54.6) in the intention-to-treat population and 55.8% (97.5% CI, 50.6 to 60.4) in the per-protocol population. Vaccine efficacy against severe malaria was 45.1% (95% CI, 23.8 to 60.5) in the intention-to-treat population and 47.3% (95% CI, 22.4 to 64.2) in the per-protocol population. Vaccine efficacy against severe malaria in the combined age categories was 34.8% (95% CI, 16.2 to 49.2) in the per-protocol population during an average follow-up of 11 months. Serious adverse events occurred with a similar frequency in the two study groups. Among children in the older age category, the rate of generalized convulsive seizures after RTS,S/AS01 vaccination was 1.04 per 1000 doses (95% CI, 0.62 to 1.64).
Conclusions
The RTS,S/AS01 vaccine provided protection against both clinical and severe malaria in African children. (Funded by GlaxoSmithKline Biologicals and the PATH Malaria Vaccine Initiative; RTS,S ClinicalTrials.gov number, NCT00866619.)
