The mosquito carries the malaria parasite

Two thousand children aged one to four will be given the vaccine in a study to measure how effective it is at preventing infection.

About 3,000 African children die of malaria every day.

A number of vaccines are being developed to prevent deaths and illness, but research into this particular vaccine, created by pharmaceutical company GlaxoSmithKline, is the most advanced.

Each year, a million more children vanish from the face of the earth because we don't have a vaccine   Dr Melinda Moree, Malaria Vaccine Initiative

Trials in Europe, the US and Gambia and Mozambique have already suggested the vaccine is safe and effective for adults.

This latest research, which will be carried out in an area where malaria is endemic, will also check the vaccine is safe for small children to take.

The children will be monitored for up to 18 months, longer than previous trials of the vaccine, to see if they develop the disease.

Prevention

In previous short-term trials of the vaccine, its effectiveness has appeared to wear off after two months. It is hoped that its protection will last longer in children.

If the trial is successful, further research will be needed.

Researchers estimate it could be between five and eight years until the vaccine, RTS,S/AS02, is available, even if the trials are successful.

When a mosquito bites, it transmits an early form of the malaria parasite called the sporozoite into the bloodstream.

From there, it moves to the liver, where the full parasite develops.

Researchers hope that by interrupting the life cycle of the parasite at the early sporozoite stage, it will be possible to arm the immune system against infection.

The vaccine is made from a surface protein from the sporozoite.

This is then combined with two substances which will trigger the immune system to attack.

Delay

Dr Pedro Alonso, who is heading the study in Mozambique, said: "We are looking at whether it could be delivered early in life in a programme where it could be delivered to young infants."

"Our team is committed to finding ways to prevent malaria from remaining the number one killer of Africa's children.

"This trial is an important contribution to that effort and brings us that much closer to the goal of immunising children against malaria."

Dr Ripley Ballou, of GlaxoSmithKline, who has been involved in the development of the vaccine, said: "We will be looking to see how many children become infected, do they develop anaemia, or other complications of malaria."

Dr Melinda Moree, director of the Malaria Vaccine Initiative which is backing the Mozambique research, said: "For each month of delay, 120,000 children die of malaria.