Vaccine Halves Malaria Infections in Young Children
Study: Vaccine Prevents About Half of Severe Infections
Oct. 18, 2011 -- An experimental vaccine cut malaria infections in infants and toddlers by about half, a new study shows.
"This is remarkable when you consider there has never been a successful vaccine against a human parasite nor obviously against malaria," study researcher Tsiri Agbenyega, principal investigator of the study at Agogo Presbyterian Hospital in Agogo, Ghana, says in a news briefing.
The study is the largest test to date of the vaccine, called RTS,S, which has taken 20 years and more than $400 million to develop.
Final results of the trial aren’t expected until 2014, but if preliminary findings hold, experts say the vaccine will be a major advance against one of the world’s leading infectious disease killers.
“This is the first time anybody has been able to reach this point,” says Alberto Moreno, MD, an assistant professor of infectious disease at Emory University School of Medicine in Atlanta. Moreno has studied malaria for more than 35 years, but he was not involved in this study. “In the field, it will have a significant impact.”
The study is published in the New England Journal of Medicine.
Malaria is caused by a parasite that’s most commonly passed to humans through the bite of an infected mosquito.
Although malaria has been eradicated in the U.S. since the 1950s, in other parts of the world it continues to be a major public health menace, causing more than 225 million infections each year and killing nearly 800,000 people. Most of those deaths occur in children in Africa.
So far, scientists have identified five different species of parasites that are responsible for causing malaria infectious. The new vaccine targets the deadliest.
Preventive efforts like bed nets, mosquito spraying, and medications to help control the infection “have made a tremendous dent in malaria, but despite that, over 700,000 children still die every year,” says researcher Mary J. Hamel, MD, a malaria epidemiologist at the CDC and a principle investigator on the RTS,S Malaria Vaccine Trial in Kenya. “So a vaccine like this, with 50% efficacy against severe disease, can have a very important role in controlling malaria and reducing the burden.”