Immune children studied in hunt for malaria vaccine

  • 26/05/2014

Scientists hunting for a new vaccine for malaria have recruited the help of a group of Tanzanian children who are naturally immune to the disease.

Researchers in the US have discovered the immune children produce an antibody that attacks the parasite which causes malaria.

By injecting a form of this antibody into mice they found the animals became protected from the disease.

The team behind the research, who published their results in the journal Science, say trials on primates and humans are now needed to get a fuller assessment of the vaccine's potential.

Director of the Center for International Health Research Professor Jake Kurtis said, "I think there's fairly compelling evidence that this is a bona fide vaccine candidate. However it's an incredibly difficult parasite to attack.

"It's had millions of years of evolution to co-opt and adapt to our immune responses - it really is a formidable enemy."

The researchers began by taking regular blood samples from 1,000 children in Tanzania in the first years of their lives. They found that 6 percent developed a natural immunity to malaria despite the fact that they lived in areas where the disease is prevalent.

Prof Kurtis says, "There are some individuals who become resistant and there are some individuals who do not become resistant. We asked what were the specific antibodies expressed by resistant children that were not expressed by susceptible children."

Those children that are resistant, it was found, produced an antibody that attacks the malaria parasite at a vital stage in its life-cycle by trapping the tiny organism in red blood cells and preventing it from bursting out and spreading into the rest of the body.

The tests carried out in mice give hope that the antibody could possibly be used to create a vaccine.

Prof Kurtis says, "The survival rate was over two-fold if the mice were vaccinated compared to unvaccinated - and the parasitemia [the number of parasites in the blood] were up to four-fold lower in the vaccinated mice."

source: newshub archive