Malaria Vaccine

Share
|

Science, Aug 8, 2013, DOI: 10.1126/science.124800, reports a new highly successful Malaria vaccine. Stephen Hoffman's intravenous (IV) vaccine consists of live attenuated plasmodium falciparum sporozoites -- labeled pfspz.

In a group of volunteers given four or five intravenous injections of the vaccine: 0/6 of the volunteers receiving five injections contracted malaria when later inoculated (p=0.018); 3/9 of the volunteers given only four injections (p=0.028); and 5/6 of the untreated volunteers contracted malaria. Despite the small population, the results were significant.

Prior experiments had shown that multiple mosquito bites by infected but radiated Mosquitos induced immunity. Hoffman took the process forward in employing numbers of radiated sporozoites. Sub-cutaneous injections did not work well, but the intravenous injections did.

Logistics in Africa may pose a problem in that the vaccine requires delivery in liquid Nitrogen containers. The IV dosing may not be so difficult because the volume is quite small, but getting patients back for four more injections likely will be. The authors suggest including the malaria vaccine along with other routinely delivered frozen veterinary products as a feasible avenue. Go.nature/mae5tu has a helpful summary on the background development of the vaccine.

Prior malaria vaccination attempts proved only slightly effective. Malaria remains, despite slow improvement, the number one killer worldwide with deaths estimated by WHO to be between 490,000 and 836,000 in 2010 and cases worldwide between 154 million and 289 million.

Global warming may once again result in Malaria's spread to northern regions, as p. vivax did in the first half of the twentieth century as far north as Archangel, Russia. (Lat: 64.5333)

The emergence of an effective vaccine comes at a good time. It remains to be seen if the vaccine works on other than the p. falciparum variety and on young children.