Navy Capt. Judith Epstein, clinical director of the Naval Medical Research Center, Malaria, told a military health care symposium ln Kissimmee, Florida, last week that recent tests "bring us closer to having a malaria vaccine to prevent infection and disease in military personnel deployed to malaria-endemic regions, as well as vulnerable populations residing in malaria-endemic regions."
At an Aug. 22 session on "What's New in Infectious Disease Research in the Tropics," Epstein said that malaria "has consistently been ranked as the number-one infectious disease threat facing the military, and the burden of malaria remains incredibly high worldwide."
Malaria, transmitted by infected female Anopheles mosquitoes, can bring on fever, fatigue, vomiting, and headaches, and in severe cases can be fatal. There can be recurrences months and years later in untreated cases.
In 2016, there were 216 million cases of malaria worldwide, resulting in an estimated 445,000 to 731,000 deaths, according to the World Health Organization. The recommended treatment for malaria is a combination of antimalarial medications that includes an artemisinin.
No effective vaccine has ever been developed, but Epstein said that research on a vaccine using a purified form of one of the early stages of the malaria parasite has been encouraging.
The altered parasites appeared to produce an immune response and did not lead to infection or disease, according to a release from the Naval Medical Research Center (NMRC).
Last year, Epstein was principal investigator for a "Warfighter 2 Trial" of the vaccine conducted at NMRC and the Center for Vaccine Development at the University of Maryland, Baltimore (UMB).
At NMRC and UMB, a total of 60 subjects were given the vaccine and then exposed to five bites from malaria-infected mosquitoes.
The researchers "were able to demonstrate vaccine efficacy of 40 percent against a non-vaccine strain of malaria when assessed 12 weeks after the final injection, a marked improvement from the previous trials," the release said.
"In all trials, the vaccine has been demonstrated to have a very good safety and tolerability profile and has also been easy to administer," Epstein said. "Our focus now is to enhance the efficacy and practical use of the vaccine."
-- Richard Sisk can be reached at Richard.Sisk@Military.com.