Genetics help explain poor showing for GSK malaria vaccine

Now scientists have discovered that genetic variability in a protein found on the surface of malaria parasites may help explain the patchy response because, while the protein comes in different forms, GSK's vaccine incorporates only one variant.

The new study, funded by the U.S. National Institutes of Health, looked at blood from 5,000 youngsters and found that the vaccine gave less protection when toddlers were infected with parasites with a different protein variant to the vaccine.

GSK said the research was interesting but early-stage.

"This single study is too small to offer conclusive evidence for how RTS,S should be deployed," a spokeswoman said.

"However, the work underscores how a full and comprehensive catalogue of the genetic diversity of key pathogens could inform the design of clinical studies in the future," she said.

Experts advising the World Health Organization (WHO) have been meeting in Geneva this week to draw up recommendations on how the vaccine could be used. The U.N. agency, which normally follows such advice, will make a recommendation by November.

Even if the WHO view is positive, the vaccine is unlikely to be rolled out widely before 2017 since it still needs to win funding from international donors and be approved by governments in the African countries where it will be used.

GSK has said it will not make any profit from the vaccine, since it will be priced at the cost of manufacture plus a five percent margin, which will be reinvested in research on malaria and other neglected tropical diseases. (By Ben Hirschler, editing by David Clarke)