英国研究人员日前开发出一种可同时对多种疟原虫起作用的广谱疟疾疫苗，它已经在人类血液样本实验和动物实验中验证有效。
英国爱丁堡大学等机构研究人员在新一期《科学公共图书馆—综合》杂志上报告说，这种疫苗可以引起人体内多种抗体的反应，能够同时对付一系列的疟原虫。疟原虫是引发疟疾的罪魁祸首，但由于疟原虫有许多种类，现有疫苗往往只能对付部分种类的疟原虫，效果不是很理想。
本次研究发现，所有种类的疟原虫都含有一种关键的蛋白质，只是这种蛋白质会在不同疟原虫中表现出不同类型。因此，研究人员以这种蛋白质作为突破口，把不同类型的蛋白质联合到一起进行研究，在此基础上开发出的疫苗就可以同时对多种疟原虫都产生效果。
研究人员在疟疾多发的非洲地区提取了人类血液样本进行实验，表明这种广谱疫苗能够有效预防疟疾。此外，这种疫苗在动物实验中也显示有效。研究人员接下来计划进行人类临床试验。（生物谷 Bioon.com)
doi:10.1371/journal.pone.0026616
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A Malaria Vaccine Based on the Polymorphic Block 2 Region of MSP-1 that Elicits a Broad Serotype-Spanning Immune Response
Graeme J. M. Cowan1, Alison M. Creasey1, Kelwalin Dhansarnsombut1, Alan W. Thomas2, Edmond J. Remarque2, David R. Cavanagh1*
Polymorphic parasite antigens are known targets of protective immunity to malaria, but this antigenic variation poses challenges to vaccine development. A synthetic MSP-1 Block 2 construct, based on all polymorphic variants found in natural Plasmodium falciparum isolates has been designed, combined with the relatively conserved Block 1 sequence of MSP-1 and expressed in E.coli. The MSP-1 Hybrid antigen has been produced with high yield by fed-batch fermentation and purified without the aid of affinity tags resulting in a pure and extremely thermostable antigen preparation. MSP-1 hybrid is immunogenic in experimental animals using adjuvants suitable for human use, eliciting antibodies against epitopes from all three Block 2 serotypes. Human serum antibodies from Africans naturally exposed to malaria reacted to the MSP-1 hybrid as strongly as, or better than the same serum reactivities to individual MSP-1 Block 2 antigens, and these antibody responses showed clear associations with reduced incidence of malaria episodes. The MSP-1 hybrid is designed to induce a protective antibody response to the highly polymorphic Block 2 region of MSP-1, enhancing the repertoire of MSP-1 Block 2 antibody responses found among immune and semi-immune individuals in malaria endemic areas. The target population for such a vaccine is young children and vulnerable adults, to accelerate the acquisition of a full range of malaria protective antibodies against this polymorphic parasite antigen.
