Malaria Vaccine Is Given a Good Shot as Big-Money Donors Boost Research
LONDON — The fight against malaria, one of the world’s biggest killers, has just gotten a booster.
An experimental vaccine has shown promise in two studies in African children, who account for the majority of the more than one million victims that malaria claims every year. Published online Monday in the New England Journal of Medicine, the studies affirm encouraging results from earlier trials of the vaccine, known only as “RTS,S.” It is being developed by GlaxoSmithKline PLC and the Path Malaria Vaccine Initiative, or MVI, a charitable group funded by the Bill & Melinda Gates Foundation.
“We are one important step closer to the date when malaria will join diseases like smallpox and polio, that have been either eradicated or controlled by vaccines,” Christian Loucq, director of MVI, said of the results. If the vaccine does well in a larger study to determine whether the shot is truly safe and effective, it could be ready for use as soon as 2011.
The development illustrates how some deep-pocketed charities are breathing new life into research for potentially life-saving drugs that pharmaceutical companies saw as too risky or unprofitable to pursue.
In 1999, as Glaxo was planning to abandon the malaria vaccine amid scepticism about markets, the Belgian unit doing the research made the unusual move of applying for a grant from the Gates Foundation. Since then, the foundation has poured some $107.6 million into developing the vaccine, through a grant to MVI. Gates and other charities are also funding research to find vaccines or treatments for tuberculosis and AIDS. Glaxo says it has invested $300 million in the malaria vaccine to date.
Malaria, a parasitic infection spread by mosquitoes, exacts a human and economic toll, particularly in sub-Saharan Africa. The disease strikes children as well as adults, sometimes removing them from the work force for long periods of time. According to MVI, the disease costs African nations roughly $12 billion a year.
Researchers have been searching for a malaria vaccine for decades, but the complexity of the malaria parasite has made for tough work. The best way to prevent malaria today is through bed nets and insecticides that keep mosquitos at bay. Drugs to treat malaria also exist, but the parasite often develops resistance to these medicines. The drugs are also in short supply in some parts of the world.
Ideally, any vaccine would be given to babies in endemic countries as part of their regular pediatric immunizations.
One study published Monday in the New England Journal of Medicine involved 340 infants in Tanzania. All infants were given standard pediatric immunizations against a range of diseases, including diphtheria, tetanus and polio. In addition, half the group got the malaria vaccine, and the other half a hepatitis B vaccine to make sure both groups had the same number of shots.
The main goal of the trial was to test the safety of the malaria vaccine, and to see whether it interfered with the other pediatric shots. The malaria vaccine showed no “obvious safety concerns” and no interference with the other immunizations, the study’s researchers wrote in the NEJM. In the group receiving the malaria vaccine, the risk of getting infected with malaria was reduced by 65%, when compared with the other group.
In a separate trial aimed at testing the vaccine’s efficacy, researchers used a slightly different version of the malaria vaccine — one containing a different adjuvant, a substance meant to enhance the vaccine’s properties. Researchers vaccinated 809 children in Kenya and Tanzania with either the malaria vaccine or a rabies vaccine. After about eight months, 32 of 402 children in the malaria vaccine group, or 8%, developed clinical malaria, versus 66 of 407 children, or 16%, in the rabies-shot group.
Two scientists from the Centers for Disease Control and Prevention in Atlanta wrote an editorial in the NEJM calling the results “promising.” But they noted that the studies were carried out in countries where use of bed nets and anti-malarial drugs have dramatically reduced the number of malaria cases. The vaccine needs to be tested in areas with higher rates of malaria, they said.
“This is the first malaria vaccine to reach this stage of development, and it will be essential to learn how it performs in areas of more intense transmission,” the scientists wrote. “It is, indeed, a hopeful beginning.”