来自RTS，s第三阶段的试验引起了媒体的极大兴奋，谈到了“世界上第一种疟疾疫苗” and its potential to “save 200,000 lives a year”.

RTS，s是由Glaxo Smith Klein（GSK）和Path Malaria疫苗倡议（MVI）合作开发的，并在八个不同非洲国家的13个中心进行了试验。它目前正在进行III期评估，使其成为疟疾临床最先进的疫苗候选者。在令人鼓舞的结果之后，GSK表示意图申请欧洲药品局（EMA）的批准¹该疫苗将在2015年底由世界卫生组织（WHO）评估，以获取政策建议²。

该疫苗源自疟原虫的孢子岩阶段的外孢菌岩蛋白（CSP），并在GSK中配制ASO1佐剂。因此，正是这些寄生虫的肉毒pre肉前卵菌阶段是宿主对疫苗的免疫反应的目标。直到寄生虫通过肝脏并发展成红细胞形式，它们才引起疾病的症状。通过针对寄生虫的这些早期阶段，该疫苗希望降低发病率和死亡率。³

世卫组织估计，每年有2.19亿例疟疾病例和660,000例死亡，其中90％在非洲⁴。较早的研究表明，在5-17个月大的儿童中，RT将疟疾的发病率降低到约50％，在6-12周之间的婴儿中，RTS的发病率降低了30％，两个年龄段的RT降低了疾病严重程度的降低百分比。³这使我们回到了头条新闻 - 建议这种疫苗每年可以节省多达200,000人的生命。

It’s not that simple, of course. Recent analyses showed that vaccine efficacy decreased with increasing exposure to malaria and with time, so much so that vaccine efficacy had generally decreased to zero in the four years following vaccination, indicating a need for a booster vaccine.⁵

Overall, the vaccine does significantly reduce the number of cases of malaria (see fig 1) but with all the hype in the media as each set of results are released, it’s a concern that the general public might perceive the new vaccine as a “magic bullet”, and perhaps even the end of taking all those tablets and sleeping under sweaty bed nets when you go on holiday.

The battle against malaria is complicated by the parasite’s life-cycle. There is massive amplification of asexual parasites in the blood in the human host as well as amplification in the mosquito stages during the development of infective sporozoites. A vaccine such as RTS,S that targets the human stages of the parasite will reduce transmission from the human host to the mosquito vector, but ideally needs to be used in conjunction with measures that prevent transmission from mosquito to human i.e bed nets, repellents, insecticides etc or a transmission blocking vaccine (TBVs).³rts，s将会并且始终打算用作控制和possiblythe eradication of malaria- even the WHO reports that “RTS,S/AS01 will be evaluated as an addition to, not a replacement for, existing malaria prevention, diagnostic and treatment measures”²。

因此，请勿将床网和疟疾片扔掉。

References

1. https:// www.bbc.co.uk/news/health-24431510
2. 疟疾政策咨询委员会摘要回复：RTS，S/ ASO1疟疾疫苗，https://www.who.int/malaria/mpac/rts_summary_brief_mpac_march_2013.pdf
3. Malaria vaccine R&D in the Decade of Vaccines: Breakthroughs, challenges andOpportunities. 2013. A J. Birkett, V S. Moorthyb, C. Loucq, C E. Chitnis & D C. Kaslow.疫苗。31s：B233– B243
4. WHO. World Malaria Report 2011, https://www.who.int/malaria/world malariareport 2011/en/
5. Four-Year Efficacy of RTS,S/AS01E and Its Interaction with Malaria Exposure. 2013. A. Olotu, G. Fegan, J. Wambua, G. Nyangweso, K O. Awuondo, A. Leach, M. Lievens, D. Leboulleux, P. Njuguna, N. Peshu, K. Marsh & P. Bejon. NEJM.368:12，，，，1111-1120.