Tanzanian children will be among the first in Africa to benefit from a malaria vaccine developed following a successful medical research. The vaccine has been proved to give significant protection against clinical and severe malaria while showing an acceptable safety profile.Researchers say the efficacy and safety results in six to 12-week-old infants would come out by the end of 2012 and added that the findings on the longer-term protective effects of the vaccine, 30 months after the third dose should be available by the end of 2014.
The report showing first results from a large-scale phase three trial of RTS,S vaccine were unveiled yesterday by the National Institute for Medical Research (NIMR) in Dar es Salaam. They indicated that three doses of the vaccine reduced the risk of children experiencing clinical malaria and severe malaria by 56 per cent and 47 per cent, respectively.
The trial of the vaccine was conducted in 11 sites in seven countries across sub-Sahara Africa, including Tanzania where the study took place at Korogwe and Bagamoyo. Other countries were Burkina Faso, Ghana, Gabon, Kenya, Malawi and Mozambique. According to the report, the analysis was performed on data from the first 6,000 children aged five to 17 months, over a 12-month period following vaccination, out of the total of 15,460 infants and children enrolled in the pilot study.
Regarding safety, the presentations made by Dr Salim Abdulla, the principal investigator of the trial for Bagamoyo site and Dr Samwel Gesase of Korogwe pointed out that the overall incidence of Serious Adverse Events (SAEs) comparable between the RTS,S/AS01 vaccine which was 18 per cent and those receiving a control vaccine was 20 per cent.
An analysis of severe malaria episodes so far reported in all the children enrolled in the study showed 35 per cent efficacy over a follow-up period ranging between 0 and 22 months (average 11.5 months).
The Director of Preventive services in the ministry of Health and Social Welfare, Dr Donan Mmbando, said the results were a milestone in the fight against malaria in the country as it celebrates 50th anniversay of independence.
He said malaria, which is preventable, was claiming more than 20,000 lives in the country annually, most of whom being expectant mothers and children under the age of five. He said 60 to 80 per cent of deaths occurred at home before patients reached a health facility. He, however, expressed optimism that the vaccine, coupled with other malaria control interventions such as treated mosquito nets would reduce the number of deaths in the country significantly.
"My ministry will include the vaccine in the national health system if all safety and efficacy indications prove positive as demonstrated in this first result of phase three" he said. According to NIMR, malaria incidents occur in approximately 225 million people worldwide each year killing about 781,000 of them, mostly those in Africa. Malaria remains the major health threat in Africa.
The results show that the RTS,S vaccine has consistently shown protection against Plasmodium falciparum malaria in children and infants since phase two trials.
The bigger advantage of the vaccine according to the report is that it can be administered safely with other childhood vaccines without restrictions or complications.
From March 2009 through January 2011, the researchers randomly assigned 15,460 children to one of the three original groups in a one-one-one ratio and comparator vaccines; rabies vaccine for children of 5 to 17 months of age was administered at enrollment and minningococcal serogroup for children of six to 12 months. Passive surveillance for malaria was thereafter undertaken from the time of administration of the first dose of vaccine until the end of the study whereas the participants were encouraged to seek care at health facilities within the study area for any illness.
for which transportation was facilitated.
According to the research team, the study was conducted with rigorous among the centres and provided a high standard of clinical care.
The 25-year research was financed by the Bill and Melinda Gates Foundation with more than US$200 million (about sh300 billion) in grant monies. Another $50-100 million (about sh80 - sh170 billion) would be invested before the completion of the project.