Tuesday, October 18, 2011

First Malaria Vaccine Successful in a Major Clinical Trial

What great news!
An experimental vaccine from GlaxoSmithKline halved the risk of African children getting malaria in a major clinical trial, making it likely to become the world's first shot against the deadly disease.

Final-stage trial data released on Tuesday showed it gave protection against clinical and severe malaria in five- to 17-month-olds in Africa, where the mosquito-borne disease kills hundreds of thousands of children a year.

"These data bring us to the cusp of having the world's first malaria vaccine," said Andrew Witty, chief executive of the British drugmaker that developed the vaccine along with the nonprofit PATH Malaria Vaccine Initiative (MVI).

While hailing an unprecedented achievement, Witty, malaria scientists and global health experts stressed that the vaccine, known as RTS,S or Mosquirix, was no quick fix for eradicating malaria. The new shot is less effective against the disease than other vaccines are against common infections such as polio and measles.

"We would have wished that we could wipe it out, but I think this is going to contribute to the control of malaria rather than wiping it out," Tsiri Agbenyega, a principal investigator in the RTS,S trials in Ghana, told Reuters at a Seattle, Washington, conference about the disease.

Malaria is endemic in around 100 countries worldwide and killed some 781,000 people in 2009, according to the World Health Organization.

Control measures such as insecticide-treated bednets, indoor spraying and use of combination anti-malaria drugs have helped significantly cut the numbers of malaria cases and deaths in recent years, but experts have said that an effective vaccine is vital to complete the fight against the disease.

The new data, presented at the Bill & Melinda Gates Foundation's Malaria Forum conference in Seattle and published simultaneously in the New England Journal of Medicine, were the first from a final-stage Phase III clinical trial conducted at 11 trial sites in seven countries across sub-Saharan Africa.

The trial is still going on, but researchers who analyzed data from the first 6,000 children found that after 12 months of follow-up, three doses of RTS,S reduced the risk of children experiencing clinical malaria and severe malaria by 56 percent and 47 percent, respectively.
Thanks to funding from the Bill and Melinda Gates Foundation, this breakthrough was achieved. Malaria has plagued the poor third world for centuries and finally there is some hope to cut down on the number of people who die from this parasitic disease.
Malaria is caused by a parasite carried in the saliva of mosquitoes. The RTS,S vaccine is designed to kick in when the parasite enters the human bloodstream after a mosquito bite. By stimulating an immune response, it can prevent the parasite from maturing and multiplying in the liver.

Without that immune response, the parasite gets back into the bloodstream and infects red blood cells, leading to fever, body aches and in some cases death.
Althouhg most health experts like to see an effective rate of 80% for most vaccines, a 50% plus rate will continue to save many lives. If everyone breaks right, the vaccine should be available in 2015.

Here is the life cycle of the malaria parasite.

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