The researchers also found that RTS,S/ASO2 could be safely and effectively given along with other childhood vaccines. The malaria vaccine did not interfere with the protective responses of other vaccines. And the effectiveness of the RTS,S malaria vaccine wasn't compromised by the other vaccines, Abdulla said.
In the second study, 894 children in Kenya and Tanzania, ages 5 to 17 months, were given either three doses of the malaria vaccine or a rabies vaccine. The researchers found a 53 percent reduction in the risk of developing malaria among children who received the RTS,S vaccine.
"If these findings were replicated in a Phase III multi-center study, we would expect that study to lead to an application for a license for RTS,S/AS01 as a vaccine to prevent clinical malaria," said lead researcher Philip Bejon, of the Kenya Medical Research Institute (KEMRI)-Wellcome Collaborative Research Programme and the Centre for Tropical Medicine at the University of Oxford, in England.
"The vaccine would be only partially effective, but may still be a useful addition to malaria control programs," Bejon added.
The differences in the results of the two trials can be explained by what the researchers were looking for. In the first trial, the scientists looked for the presence of malaria in the infants' blood; in the second trial they looked for children who actually went on to develop the disease.
It's unclear how long the vaccine would be effective. But, in a four-year follow-up of children given the vaccine in Mozambique, the inoculation remained effective in preventing most cases of malaria, Loucq said.
Phase III trials of the vaccine are set to begin early next year, he said.
The vaccine trials were funded by a grant from the Bill & Melinda Gates Foundation to the PATH Malaria Vaccine Initiative, and drug maker GlaxoSmithKline.<
All rights reserved