Promising step for world’s first malaria vaccine

The search for the world’s first malaria vaccine received a boost with the release of early results from a major clinical trial showing it cut risk by about half in African children.

The vaccine known as RTS,S is made by the British pharmaceutical giant GlaxoSmithKline’s lab in Belgium, and is the first of its kind to attempt to block a parasite, rather than bacteria or viruses.

Experts hailed the phase III trial under way at 11 sites in sub-Saharan Africa as a promising step toward eradicating the ancient mosquito-borne disease that kills almost 800,000 people yearly, most of them children.

The results are published online in the New England Journal of Medicine, and were simultaneously announced at the Malaria Forum hosted by the Bill & Melinda Gates Foundation in Seattle, Washington.

In a statement, philanthropist and Microsoft tycoon Bill Gates described the findings as a “huge milestone” in the fight against malaria, that “has the potential to protect millions of children and save thousands of lives”.

Children aged five to 17 months who received three doses of the vaccine saw a 56 per cent lower risk of developing clinical malaria, which causes high fever and chills, according to the study.

When it came to severe malaria – the stage of the illness that can be fatal and reaches the blood, brain or kidneys – those who received the vaccine showed a 47 per cent lower risk.

“This is remarkable when you consider that there has never been a successful vaccine against a human parasite,” said Tsiri Agbenyega, who chairs the RTS,S Clinical Trials Partnership and heads malaria research at Komfo-Anokye Teaching Hospital in Kumasi, Ghana.

“While these results are encouraging, we still have a ways to go,” he told reporters.

The analysis was done with data from 6,000 children in the trial over a 12-month follow up after vaccination.

More data is needed from the younger age group – infants aged six to 12 weeks – to better assess how well it works in this particularly vulnerable group, experts said. Additional results from the younger set are due next year.

The World Health Organisation says malaria claimed 781,000 lives in 2009. About 90 per cent of malaria deaths each year occur in Africa and 92 per cent of those are children less than five years old. More than 15,000 children in seven African countries are enrolled in the trial, which is set to continue for two more years, and covers areas with other interventions in place against malaria, such as bed nets and spraying.

RTS,S was created in 1987 in GlaxoSmithKline Biologicals’ lab in Belgium. Testing began on healthy adults in Europe and the United States in 1992, before the first Africa study started in Gambia in 1998.

Trial sites are now located in Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique and Tanzania, including 15,460 infants and young children in what GSK described as “the largest malaria vaccine trial to date”.

The vaccine works by triggering the immune system to defend the body against Plasmodium falciparum, the deadliest type of malaria parasite.

Several questions remain, including how long the vaccine may last and how much it will cost, said Seth Berkley, chief executive officer of the Global Alliance for Vaccines and Immunisation.

Malaria “is a huge problem for the poorest of the poor, and there has been a search for vaccines for as long as I can remember,” he remarked. “So to have success, even if not perfect, is a really big deal”.