The latest clinical trial of the world's leading malaria vaccine candidate produced disappointing results Friday. The infants it was given to had only about a third fewer infections than a control group.

But researchers said they want to press on, assuming they keep getting financial support, because the number of children who die of malaria is so great that even an inefficient vaccine can save thousands of lives.

Three shots of the vaccine, produced by GlaxoSmithKline, gave babies fewer than 12 weeks old 31 percent protection against detectable malaria and 37 percent protection against severe malaria, according to an announcement by the company at a vaccines conference in Cape Town, South Africa.

Last year, in a trial in children up to 17 months old, the same vaccine gave 55 percent protection against detectable malaria and 47 percent against severe malaria.

The new trial "is less than we'd hoped for," Moncef Slaoui, Glaxo's chairman of research and development, said. "But if a million babies were vaccinated, we would prevent 260,000 cases of malaria a year. This is a disease that kills 655,000 babies a year -- 31 percent of that is a very large number."

The company, which has already spent more than $300 million on the vaccine, wants to keep forging ahead, he said, "but it is not just our decision."

It also depends on the PATH Malaria Vaccine Initiative, which has put more than $200 million of its Bill and Melinda Gates Foundation financing into the vaccine, and on the World Health Organization, which has helped talk seven African countries into allowing the vaccine to be tested on their children. The Gates Foundation declined to say how much money it was ultimately prepared to spend.