Malaria was eradicated in the U.S. by 1951, so Americans can be forgiven for not giving the disease much thought. But the mosquito-borne scourge is responsible for the deaths of nearly a million children under age 5 each year — mostly in Africa — killing one child every 30 seconds. Half the world's population remains at risk — including travelers to affected countries.

But while initiatives to provide insecticide-treated bed nets and other control measures have cut malaria rates in half in some countries, the disease is adapting, and insecticide-resistant and treatment-resistant strains are increasingly problematic. And the worldwide recession is reducing the funding available to keep malaria-control initiatives going. As a new avenue of attack, the PATH Malaria Vaccine Initiative (MVI) — which is funded by the Bill & Melinda Gates Foundation — on Friday, Jan. 15, announced a collaboration with the Johns Hopkins Bloomberg School of Public Health and the Sabin Vaccine Institute to create a whole new kind of malaria vaccine. Called a transmission-blocking vaccine (TBV), it is aimed not at protecting individuals from the disease but at preventing mosquitoes that carry it from spreading it.

"I think it's very encouraging," says Dr. Lee Hall, chief of the Parasitology and International Programs branch of the National Institute of Allergy and Infectious Diseases (NIAID). "It's a big endorsement by MVI for this general approach."

Traditional vaccines work by introducing a killed or weakened version of a disease into the body, where the immune system spots it and cranks out antibodies against it. Then, if a wild strain of the pathogen comes along later — one that has the power to sicken or kill — the body is ready for it. The new approach is different. Developed by Rhoel Dinglasan, an entomologist and biologist at Johns Hopkins University Hospital, it would instead work within the mosquito gut.