WASHINGTON, Sept. 8 (UPI) -- As one type of malaria parasite has become resistant to all drugs, researchers have identified a new compound that prevented mice from being infected with the disease.
A single dose of a novel compound prevented malaria infection in mice for 30 days, preventing infection in the liver and killing parasites in the blood, report researchers at Harvard University and the Massachusetts Institute of Technology in a study published in the journal Nature.
There were about 214 million cases of malaria worldwide in 2015, with about 438,000 people dying, most of them children. Standard treatments for infection by the Plasmodium falciparum parasite, carried by mosquitoes, have been failing for several years, leading to stepped-up efforts to find a vaccine.
While malaria has long been a problem in developing nations, and especially Africa, the P. falciparum parasite was found to be resistant to all treatments along the border of Cambodia and Thailand.
Researchers in the new study scanned more than 100,000 potential treatments, arriving at a compound to target the enzyme phenylalanyl-tRNA synthetase. In mice, a single dose of the compound prevented the parasite from infecting the liver and killed it as it circulated through the rodents' blood in multiple trials.
"The advantage of a single dose antimalarial is that it potentially reduces costs and removes the issue of patients not completing the course of treatment," David Baker, a professor at the London School of Hygiene and Tropical Medicine who was not involved with the new study, told The BBC. "One of the safety tests they ran on the new compounds gave results suggesting that there may be a degree of toxicity in human cells, but hopefully the chemists will be able to modify the compounds to remove this issue."
The new compound is not the first study to posit a successful vaccine against malaria this year, though others have shown hope in humans, not testing in an animal model.
In May, researchers at the University of Maryland tested the PfSPZ Vaccine in a small phase 1 trial showed varying numbers and levels of doses were safe and could be effective.
The World Health Organization also has been involved with the development of the RTS,S vaccine, which released the results of a phase 3 clinical trial showing it protected between 18 percent and 39 percent of children participating in the trial.
Researchers at Walter Reed Army Research Institute found in a small study of RTS,S with adults that changes to the vaccine regimen could improve its efficacy. Researchers involved with the study say, however, that more and larger tests of the method are needed and that results will not be available for several years.