Fresh hopes for malaria vaccine

14 August 2013 11:34

Researchers in the US have been testing an effective malaria vaccine

Researchers in the US have been testing an effective malaria vaccine

Scientists appear to have produced an effective vaccine to give total protection against malaria.

Researchers from the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, produced an intravenous vaccine made from whole cells of the malaria organism that had been weakened by radiation.

Initially a "proof of concept" study, the research could go some way towards the production of a 100% effective malaria vaccine.

The disease is caused by a single cell parasite called Plasmodium, which is spread by Anopheles mosquitoes.

According to the World Health Organisation, some 220 million people suffered the effects of a bite in 2010, with sub-Saharan Africa seeing the greatest number of casualties.

The deadliest form of the organisms, Plasmodium falciparum (Pf), is well known there, highlighting the need for medical travel insurance for anyone expecting to travel abroad.

Named PfSPZ, the new vaccine was developed by using whole Plasmodium falciparum sporozoites (SPZs), a mobile immature form of the parasite.

Sporozoites weakened by radiation had already been shown in theory to be an effective immunisation for people bitten by mosquitoes.

In order to produce the new injection, the parasite had to be sufficiently weakened but still active.

The results, which involved 40 US adults aged 18 to 45 receiving differing doses, or none at all, of the vaccine, are published in the journal Science.

The volunteers were fist bitten and infected by malaria-carrying mosquitoes, ensuring that all received aftercare treatment.

Six volunteers who received five doses of the vaccine showed to be fully protected against the infection, while six out of nine who were given four doses produced the same result.

The researchers, led by Dr Robert Seder, wrote: "These data indicate there is a dose-dependent immunological threshold for establishing high-level protection against malaria that can be achieved by IV (intravenous) administration of a vaccine that is safe and meets regulatory standards."