New YORK (Reuters Health) – an experimental vaccine against malaria proved to be not effective in field trials, except when the participants were infected with a specific strain of the parasite that causes the disease.
The study carried out in Mali revealed 48.4 percent of cases of malaria among 199 African children vaccinated and a 54.4 per cent of cases in 201 children immunized against rabies as a placebo (control group). The difference was not statistically significant.
But Dr Christopher Plowe, of the school of Medicine of the University of Maryland, in Baltimore, found that the results published in the New England Journal of Medicine, internet Edition are encouraging because the vaccine should attack the parasite in the blood, the stadium in which appear the symptoms.
“En.” the first time that a blood-stage vaccine offers some level of protection against clinical malaria “Attenuates the stadium that causes illness and death”, expressed.
Plowe explained that the species of the parasite against which the vaccine proved most promising represents between 3 and 12 per cent of cases of malaria.
In addition to this vaccine, developed at the Institute of research of the Army Walter Reed in United States, and known as FMP2.1/AS02 (A), there are other 17 vaccines against malaria are being tested, according to the World Health Organization (who).
The who estimates that there are 247 million cases of malaria in the world and 718.000 deaths per year.
Malaria is the leading cause of death and disease in Mali. The team assessed 745 children aged between 1 and 6. 400 Participants received at least one intramuscular doses (at 367 them were three doses). The injections were applied with monthly intervals and 383 children is them he controlled six months more in the season of malaria.
“Vaccine not provided a high level of protection against clinical malaria, but according to secondary outcomes would be effective for a species of parasite,” advises the team. Not attributed deaths or adverse effects serious.
In a previous trial, the vaccine, for the clone 3D7 of the species Plasmodium falciparum, had elevated levels of antibodies in blood
The National Institute of Allergy and infectious diseases, national institutes of health and the United States Defense Department funded the study.
Source: New England Journal of Medicine, online September 2011
