A new vaccine could for the first time provide total protection against malaria and appears to be more effective than other experimental vaccines that have been tested before to prevent the mosquito-borne disease. In a small study published Thursday in the journal Science, researchers found that the experimental vaccine protected 12 of 15 volunteers from malaria infection, including all six who received the most doses.
“The results are important because they demonstrate for the first time the concept that a malaria vaccine can provide a high level of protection,” Dr. Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, told Nature magazine. He added that the findings are cause for “cautious optimism”.
The vaccine contains weakened parasites carried by mosquitoes that transmit the life-threatening infection in certain tropical areas of Africa, Central and South America, India, and Southeast Asia.
It will be tested in larger trials involving hundreds of volunteers to determine an optimal number of injections and to get a better sense of its safety and effectiveness.
Previous experimental malaria vaccines used a few parasite proteins to trigger an immune response, but they weren’t particularly effective at protecting against the infection when volunteers were vaccinated and later exposed to malaria-carrying mosquitoes.
This latest vaccine contains sporozoites (SPZ)—an immature form of the malarial parasite called Plasmodium falciparum—and is thought to generate a more robust immune response to provide greater protection.
PfSPZ was developed by Sanaria, a private company based in Rockville, Maryland, that received several million dollars in funding from the National Institutes of Health for its development.
Stephen Hoffman, a veteran malaria researcher who also led the PfSPZ clinical trial, faced many challenges in his quest to produce the vaccine, according to Nature. This included raising mosquitoes, infecting them with the parasite, irradiating them to weaken the parasite, and extracting the parasite from their salivary glands to use in the vaccine.
Dr. William Schaffner, head of the preventive medicine department at Vanderbilt University’s medical school, told CNN that it may be eight to 10 years before the vaccine can be scientifically proven, approved and distributed.