Promising results from new Ebola vaccine trial

An experimental vaccine that could be a first line defense against Ebola is showing promise against the deadly disease.

Results from a Phase 1 clinical trial conducted in Africa found that the vaccine, called RV 247, is safe and prompts an effective immune response in patients. However, more research is needed to see if it still offers protection months down the line.

The vaccine has been in development for more than five years to protect against the Ebola and Marburg viruses.

The study, conducted in Kampala, Uganda, involved 108 healthy people aged 15 to 50. Between November 2009 and April 2010, researchers split the participants into four groups: 30 people received the Ebola vaccine, 30 received the Marburg vaccine, 30 got both vaccines, and 18 were given a placebo. Each participant received three rounds of injections four weeks apart.

Four weeks after the final injection, 17 of 30 people who got the Ebola vaccine showed an antibody response, meaning they developed antibodies in the blood that would help them fight off infection. Of those who received both the Ebola and Marburg viruses, 14 out of 30 showed an immune response.

However, the results were not long-lasting, and the antibodies were not detectable 11 months after the last vaccine.

Both vaccines appeared to be safe and well tolerated. The Marburg vaccine gave one study participant a low white blood cell count, but this was the only adverse side effect noted in the study.

The study was funded by the U.S. Department of Defense Infectious Disease Clinical Research Program and U.S. National Institutes of Health Intramural Research Program, and its findings were published Tuesday in the journal Lancet.

The RV 247 vaccine is similar to another vaccine, known as VRC207, which was also proven effective in an early clinical trial on humans. In November, results of the Phase 1 clinical trial of VRC207 were published in the New England Journal of Medicine, and showed the drug elicited an immune response to Ebola in 100 percent of the study participants.

The researchers developing that vaccine say they will complete the trial by the end of the month in order to expedite the approval process with the U.S. Food and Drug Administration.