SCIENCE: Vials and Trials Inch Closer to Malaria Vaccine

By Sanjay Suri Reprint | | Print |

Sanjay Suri

LONDON, Jul 9 2003 (IPS) - The development of a vaccine against malaria could be five to eight years away, a leading researcher says.

"We will try to shorten that, but it is not going to be easy," Prof Adrian Hill, a Wellcome Trust research fellow at the Institute of Molecular Medicine at the University of Oxford told media representatives.

Hill spoke at a meeting called at the Royal Society in London on Tuesday to draw attention to the dangers of malaria that kills more than one million a year, most of them children in Africa below five years of age.

"People are more aware of the danger from Sars which has killed 400 to 500 people," Melinda Moree, director of the Malaria Vaccine Initiative based in Washington said. "Malaria kills twice as many people every day."

A vaccine against malaria has eluded scientists for years now. The old remedy, chloroquin, is now considered almost useless in the fight against malaria.

Hill gave some idea why a vaccine against malaria has proved so difficult to develop. "Most viruses carry six to 12 genes," he said. "But the malaria parasite is on another scale, it has more than 5,000 genes, different sub-sets of these surface at different stages of the disease, and a few of the genes swap around." That makes it hard to determine which gene to target. So far very few of the 5,000 or so have been looked at, he said.

Seen under the microscope, he said, the malaria parasite appears a "huge beast."

But there is hope in the mapping of the genome sequence of the parasite because "we now have the entire menu of genes," Hill says. But the search is being narrowed through studies on adults, because very few adults die of malaria. Scientists are now trying to figure which part of the parasite adults naturally counter.

A significant clinical trial begins in Mozambique next week with the vaccine RTS, S/AS02A developed by the company GlaxoSmithKline. The trial will cover 2,000 children, and its results will be announced 18 months later.

The drug has been found to be safe and immunogenic in children in trials in The Gambia and in Mozambique. The new trial will be "the largest to date in tackling malaria," says Pedro Alonso, head of the Centre for International Health at the University of Barcelona.

But while this is the biggest clinical trial to get under way, several others are proceeding. "A total of 81 vaccines are under development, and clinical trials with 18 of them are under way," Filip Dubovsky, scientific director of the Malaria Vaccine Initiative told the meeting.

"Many vaccines under development will not make it to clinical trials and many in the clinical trials will go no further," he said. But on the positive side, he said, any single development in this "vials and trials" business can turn out to be the vaccine scientists are looking for.

"We are getting closer and closer to seeing what will work," Moore said. "Even negative results are taking us a long way forward because they eliminate possibilities." New players in research will bring more progress now, she said.

Globally, she said, 65 million dollars are available for research into a vaccine for malaria. That is a relatively small amount. The United States alone has an official budget of 360 million dollars for research into a vaccine against HIV, she said.

"We need hundreds of millions of dollars for research, not just 65 million," she said. "Each month we are delayed in finding a vaccine, 120,000 people die, and in a year, a million will vanish from the face of the earth."

The Malaria Vaccine Initiative is a global programme established through a 50 million dollar grant from the Bill & Melinda Gates Foundation. But research is underfunded, Hill says, because "few drug companies can afford to develop drugs for this very poor market."

Kojo Koram, head of the epidemiology unit at the Noguchi Memorial Institute for Medical Research at the University of Ghana said that governments too are inclined to give malaria less attention than it needs. "Because it affects children, policy makers often downgrade it," he said.