"For the first time in history, scientists have completed successful human trials of a malaria vaccine that provides 100% protection against the often fatal disease.
Currently, we have no truly effective method of protecting against malaria. Even the World Health Organization had only set their sights on a vaccine with an 80% efficacy rate—and they weren’t planning to have that until 2025. Because before today, according to Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, “we have not even gotten anywhere near that level of efficacy.” But this newest incarnation has surpassed everything we thought possible.
Called PfSPZ, the vaccine is made from weakened sporozoites (SPZ), the form of the malarial parasite Plasmodium falciparum (Pf) when it’s in its initial infectious state. Even though the parasite is weakened, it’s in its whole form, thus invoking an immune response. The six human subjects that were given five intravenous doses of PfSPZ were 100% protected when they were later bitten by infectious mosquitoes—five of the six unvaccinated control participants and three of the nine people only given four doses went on to develop malaria.
Previously, most of the malaria vaccines being experimented with only used a few of the parasite’s proteins. Stephen Hoffman, head of the Maryland developing firm Sanaria, decided to test a vaccine using the whole sporozoite after researching past experiments going back to the 1970s in which strong, long-lived protection from malaria resulted from volunteers being exposed to thousands of bites from irradiated infected mosquitoes. Stefan Kappe, a malaria researcher at the Seattle Biomedical Research Institute in Washington, tells Nature:
The trial results constitute the most important advance in malaria vaccine development since the first demonstration of protection with radiation attenuated sporozoite immunization by mosquito bite in the 70s. This is a pivotal success.”