More than 2,000 people a day died from malaria in 2010, and an estimated 219 million people around the world were infected that year. Now, a team of researchers has reported what could be a key breakthrough in the hunt for a vaccine to prevent the deadly mosquito-borne disease.
The small clinical trial took place at a U.S. National Institutes of Health center in Maryland in collaboration with scientists from the Army, Navy, and the biotech company Sanaria, which developed the vaccine.
None of the six volunteers who received five doses of the trial vaccine developed malaria when exposed to bites from mosquitoes carrying one malaria strain--the first 100% protection rate ever observed in the long quest for a vaccine. In comparison, in the trial, some subjects who received fewer doses were infected, and five of the six people who had no vaccine did develop malaria (the infections are controlled, and are a commonplace procedure in malaria trials).
The scientists behind the study and others in the field are excited by the promising results, but also caution years more work is needed before a vaccine could ever be approved and available on the market.
"This is not a vaccine that’s ready for travelers to the developing world anytime soon," Schaffner told CNN. "However, from the point of view of science dealing with one of the big-three infectious causes of death around the world, it’s a notable advance. And everybody will be holding their breath, watching to see whether this next trial works and how well it works."
A number of challenges remain before this could hit the market, including scaling up the production, testing it on much larger groups of people, and figuring out how long the protection would last. Another issue is that the vaccine involved protection against only one major strain of the parasite, and it had to be administered intravenously, whereas almost all other vaccines are simply injected into the skin. Dr. Robert Seder, the principal investigator in the trial, knows there’s a lot of work ahead and says that a number of follow-up studies are planned.
This is not the only promising advance in malaria prevention in recent years. With funding from the Bill and Melinda Gates Foundation, the drug company GlaxoSmithKline has been working on Mosquirix, and early results showed that three doses cut the infection risk in half for some children in a trial conducted in seven African countries. However, a more recent study forced scientists to temper their expectations.
Today, malaria prevention involves imperfect methods: pesticides and insect repellents, mosquito nets, and for travelers to tropical nations, drugs that can reduce their risk of the contracting disease.
But one of the cheapest and once common preventative drugs, Lariam, is falling out of favor because of a high chance of severe neurological side effects, including hallucinations and violence. In The New York Times this week, David Stuart MacLean, author of an upcoming memoir, writes about the complete, lifelong amnesia he has suffered after a three-day mental fit after taking Lariam when traveling in India.
He offers relevant words of caution we should all consider when contemplating any kind of new drug or cure:
"Science is a journey, but commerce turns it into a destination. Science works by making mistakes and building off those mistakes to make new mistakes and new discoveries. Commerce hates mistakes; mistakes involve liability. A new miracle drug is found and heralded and defended until it destroys enough lives to make it economically inconvenient to those who created it."