A malaria vaccine is the Holy Grail of the medical research world—one of its most tantalizing and allusive prizes.
Time and again scientists have been on the brink of success only to have their hopes publicly and painfully dashed. The height of false hope, perhaps, was in 1984 when the NY Times ran the headline “Malaria Vaccine is Near.”
Researchers were so confident they’d cracked the code that they tested the vaccine on themselves just before flying to a conference where they expected to declare victory. They came down with malaria symptoms the morning after they landed.
The vaccine community is beginning to hope again, cautiously. The Gates Malaria Forum highlighted an important step forward for RTS,S, the world’s most clinically advanced malaria vaccine candidate.
A joint project between GlaxoSmithKline and the Gates-funded Malaria Vaccine Initiative, RTS,S works in two ways. First, it prepares the defense mechanisms of a person to recognize and respond to the malaria parasite before it encounters the genuine article. Second, it helps t-cells attack the parasite as it emerges from the liver (the first stop in the body where it multiplies some 40,000X) and begins to infiltrate red blood cells.
In 2004, RTS,S was shown to provide greater than 50% protection against infection in children 1-to-4 years old. The new study finds that among children under one, the vaccine provides 65% protection against new infections over three months.
This is significant because children 18 months and younger bear a disproportionate burden from the disease: 30% to 50% of the severe disease and deaths occur in that age group. Until now, it was unknown whether the vaccine could help shield them from malaria.
Assuming Phase III trials go as planned next year, RTS,S could be on the market by 2011. But it challenges the traditional understanding of how a malaria vaccine might work. Typically, a successful vaccine is understood to provide 90% to 100% protection. With its lower efficacy rate, RTS,S wouldn’t be a silver bullet. But it would be a powerful and welcome tool in the fight against malaria.
-Martin Edlund, Malaria No More
Tuesday to Thursday this week, Malaria No More’s Martin Edlund is live blogging on the ONE Blog from the Gates Foundation’s Malaria Forum in Seattle. Malaria No More’s mission is simple: no more deaths from malaria. Learn more and help prevent a million child deaths this year by donating a $10 bed net at www.MalariaNoMore.org.