Malaria Vaccine Becoming Reality

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A new malaria vaccine provided significant protection against malaria in African children, according to a clinical trial report published in the New England Journal of Medicine. This could be the first effective vaccine against malaria.

Malaria is a mosquito-borne infectious disease that involves high fevers, shaking chills, flu-like symptoms, and anemia. The malarial parasites multiply inside the red blood cells and break open within 48 to 72 hours, infecting more red blood cells. According to the Centers for Disease Control and Prevention (CDC),  in 2008, an estimated 190 - 311 million cases of malaria occurred worldwide and 708,000 - 1,003,000 people died, most of them young children in sub-Saharan Africa.

Plasmodium Falciparum malaria vaccine
Micrograph of ring-forms, and gametocytes of Plasmodium falciparum.
Image Credit:TimVickers

In an editorial published alongside, Dr Nicholas White from the Faculty of Tropical Medicine,  Bangkok wrote, "it is becoming increasingly clear that we really do have the first effective vaccine against a parasitic disease in humans. If there are no unforeseen disasters, the RTS,S/AS01 Plasmodium falciparum malaria vaccine should become available in just over 3 years." In RTS,S/AS01, the designation “RT” refers to approximately 190 amino acids from the carboxy terminus of the Plasmodium falciparum circumsporozoite protein. RTS is a hybrid of this polypeptide fused to the amino-terminal end of the hepatitis B virus S protein. AS01 is the adjuvant.

The clinical trial enrolled 15,460 children from March 2009 to January 2011. The children were in two age groups, 6 to 12 weeks and 5 to 17 months of age.  They were vaccinated with either RTS,S/AS01 or a non-malaria vaccine. This report is an interim report of the large phase 3 trial. The vaccination reduced the incidence of malaria by half in children 5 to 17 months of age, demonstrating significant efficacy. However, despite the  high  efficacy against severe malaria, there was no reduction in the rate of death from malaria.  The authors attribute this to the "high level of access to high-quality care provided at study facilities."

Dr White added, " It is a great achievement and an important advance, but they know that this partially protective vaccine is not the sole solution to the control and elimination of malaria."

We hope that when the complete results will be published later, it will not show questionable efficacy.

Source Article: First Results of Phase 3 Trial of RTS,S/AS01 Malaria Vaccine in African Children. The RTS,S Clinical Trials Partnership. October 18, 2011 DOI: 10.1056/NEJMoa1102287.

Additional Source: A Vaccine for Malaria. Nicholas J. White, F.R.S. October 18, 2011 DOI: 10.1056/NEJMe1111777.

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