Two Ebola vaccines still in their experimental stage, one made by GlaxoSmithKline and the other by NewLink Genetics a biotech start-up, appear safe part of the way through a clinical trial that is being carried out in the African country of Liberia, said the United States National Institute of Health.
Both vaccines are given in just one injection and are being tested for efficacy and safety on over 600 people living in Liberia in a clinical trial that is mid-stage and sponsored by the NIH.
The epidemic of Ebola that started a year ago in West Africa and has killed over 10,200 people, but a reduction in the number of new cases in the countries most affected, such as Guinea, Sierra Leone and Liberia has led to people hoping it might end.
Based upon encouraging results on safety, the study might no advance into its next phase of efficacy testing, where more volunteers are injected with the vaccine from NewLink and GSK or a placebo and assessed to determine whether they have a response from their immune system by producing antibodies to fight Ebola.
None of the volunteers is intentionally exposed to the virus, instead the immune response is determined to be an acceptable proxy of how effective the vaccine could be if someone were to be exposed.
The trail that is testing the GSK vaccine, which NIAID scientists developed, and the vaccine by NewLink, developed by Canada Public Health Agency and licensed to the biotech, began February 2 in the city of Monrovia, Liberia. Neither the researchers nor the volunteers know who was given the vaccine and who the saline injection.
Medical researchers will continue enrolling new volunteers in this trial through the end of April, hoping to reach over 1,500 participants. They hope to enroll much more women, who make up 16% of this first group, to ensure there is no gender based differences in the side effects or immune system response.
These volunteers are to be followed for over a year, with samples of blood tested at six and again at 12 months following the vaccination to determine the length of the immune response.