Each year around the globe, over 200 million people are affected by malaria.
Of the nearly 600,000 of them who die because of the disease, the vast majority are children younger than five in sub-Saharan Africa. This means that at least every minute, one child will die due to the mosquito-borne disease. Only a small fraction of children have access to the nets that protect them from mosquito bites while they sleep.
However, the landscape might be changing due to a new malaria vaccine — the first ever to produce encouraging results in a human trial.
The vaccine was administered to nearly 16,000 children ages 6 weeks to 17 months across sub-Saharan Africa during a Phase III clinical trial. The children all received a booster shot 20 to 30 months later and were monitored for the disease throughout the trial.
Children vaccinated between 6-12 weeks saw a 27 percent decrease in disease, and those who were first immunized between 5-17 months had a 46 percent decrease in malaria infections. (The researchers found that it was more effective to give the vaccine to older infants rather than newborns.) Based on current mortality numbers, that could save over 275,000 lives a year.
This is incredibly encouraging for a vaccine that has been in development for 30 years with almost no success to speak of. The results were published in The Lancet.
Why has it been so difficult to manufacture a vaccine against malaria?
Malaria is caused by Plasmodium parasite. These parasites have a high mutation rate, making them a moving target for vaccines. Adding a further layer of complexity, the parasites have to be targeted differently based on which of their four life-cycle stages they're in. Researchers have tried to compensate by combining drugs, but the different methods of delivery required has stymied these efforts.
The new vaccine was able to overcome these obstacles by attacking the parasite in the early stages of its life cycle. The vaccine signals the immune system to attack based on certain proteins on the parasite's surface. It also works on infected cells in the liver, where the parasites tend to accumulate as they get filtered from the bloodstream.
The new vaccine is called RTS,S/AS01 (but will probably be given a more memorable name before it goes to market) and is manufactured by GlaxoSmithKline.
The drug is now gearing up to enter Phase IV testing, where recipients will be monitored for severe side effects. If all goes well, RTS,S/AS01 will be ready for approval to go to market.
Congratulations are most definitely in order to the amazing researchers who have dedicated their careers to protecting and improving the lives of so many people.
"We finally have in our sights a candidate vaccine that could have a real impact on this terrible disease that affects many children during their first years of life," RTS,S/AS01 trial principal investigator Kwaku Poku Asante said in a press release.
"The large number of children affected by malaria, sometimes several times per year, means that this vaccine candidate, if deployed correctly, has the potential to prevent millions of cases of malaria."