Health 
Soon clinical trials of malaria vaccine in Gambia

If successful, it would help save the lives of millions of children. Malaria is a parasitic infection transmitted through the bite of the Anopheles mosquito.

Currently, no vaccine is licensed to protect against malaria. Anti-malarial drugs are available, but the parasite has consistently developed resistance to them, leaving millions vulnerable to the disease.

Malaria currently infects an estimated 300 to 500 million people worldwide. Another 2.3 billion are at risk of the disease, making development of a malaria vaccine a global health priority.

Those most vulnerable to malaria are children under five years of age and pregnant women.

The partners in the paediatric clinical trial are Malaria Vaccine Initiative (MVI) at PATH - Programme for Appropriate Technology in Health - and Glaxo Smith Kline Biologicals (GSK), the world's largest vaccine manufacturer. The company last year distributed over 1.1 billion doses of vaccines to 177 countries, in average of 35 per second.

The Gambian unit of Britain's Medical Research Council (MRC) will conduct the trial in Basse Santa Su, a region in eastern Gambia where malaria is endemic. The MRC has worked in Gambia for 50 years and has, according to Keith McAdam, Director of MRC/Gambia, developed a strong relationship with the community and the government.

As a result, more than 90 percent of Gambia's children are immunised against the major childhood diseases, a slightly higher rate of immunisation than in the United States.

The announcement of clinical trials of the vaccine was made in London this week. "These trials are an important step forward in creating a malaria vaccine for children in Africa," said Regina Rabinovich, MIV director at PATH. "Most of the more than one million people who die of malaria every year are African children under the age of five."

No malaria vaccine has ever been tested and found successful in children, she added.

- We are pleased to announce this major advance toward the goal of preventing malaria, said Jean Stephenne, President and General Manager, GlaxoSmithKline Biologicals on Africa Malaria Day, celebrated on 25April. "We are committed to delivering a vaccine that will protect African children from this devastating disease. These trials are a critical step in that process."

Adult female Anopheles (malaria) mosquitos sit with body and biting mouth parts in a straight line when feeding.  © Photo: WTO/TDR.

The first trial, which will involve approximately 90 children between six and 11 years of age, will test the safety and immune response of Glaxo Smith Kline's "RTS,S" vaccine. Pending positive results, two subsequent trials will test the vaccine in children between one and five years old.

The vaccine manufacturer said researchers had already safely tested the vaccine in adult volunteers in the United States, Belgium, Kenya, and The Gambia. "It demonstrated a 70 percent efficacy rate in protecting adults in The Gambia against infection over a short period of time, making it the world's only malaria vaccine candidate to have shown that level of efficacy," Stephenne said.

During the upcoming children's trials, MRC investigators will encourage families to take the normally recommended malaria prevention measures. They will closely monitor the children for at least two malaria seasons, which coincide with the annual rainy season, and treat any child who contracts malaria.

- Investigators at MRC/Gambia will carefully evaluate each child throughout the trial, said McAdam. "We are hopeful that the promising results from the adult trial will translate to a safe vaccine that will protect children for a longer period of time," he said

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By Jaya Ramachandran, IPS

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