What is the number one infectious disease killer in the world? The answer may surprise you. Despite all of the attention paid to AIDS in developing countries, the number one scourge, especially in the tropics, is malaria. There are four types of malaria parasite. The most common is Plasmodium falciparum, which is also the most deadly. Mosquito-borne P. falciparum destroys red cells, causing severe anemia. Babies and the elderly are especially at risk; malaria is the leading cause of death of children throughout the African and Indian sub-continents, and is a major killer in South America as well.
Exciting news from the National Institutes of Health: the first study to show clear safety and efficacy of a new anti-malarial vaccine. This was a Phase I trial on 57 healthy adult volunteers (Phase I trials look primarily at safety in human subjects). Not only was the vaccine found to be safe, but in an experimental group of 40 subjects who received the PfSPZ vaccine, an overwhelming majority did NOT contract malaria after being exposed to the parasite through mosquito bites. Most members of a control group that did not receive the vaccine were infected after similar exposure (note that all infected volunteers were easily treated with drugs and cured).
A few caveats are in order: 1) the recent study was only performed in adults, 2) the numbers were relatively small, 3) the vaccine must be given intravenously, and 4) supplies of the vaccine must scrupulously be keep cold, since it is made from a live attenuated variant of the P. falciparum parasite.
Nonetheless, this is the first success of a malaria vaccine. It is good news for human flourishing across the globe if the results hold up in larger trials.