Washington — The first trial in a planned series of accelerated safety studies of Ebola vaccine candidates was announced August 28 by the National Institutes of Health (NIH).
Initial human testing of an investigational vaccine to prevent the disease will begin the week of September 1, according to NIH’s National Institute of Allergy and Infectious Diseases (NIAID).
The early-stage trial will begin human testing of a vaccine co-developed by NIAID and global health care company GlaxoSmithKline (GSK) and will evaluate the experimental vaccine’s safety and ability to generate an immune system response in healthy adults.
Testing will take place at the NIH Clinical Center in Bethesda, Maryland.
The study is the first of several Phase 1 clinical trials that will examine the investigational NIAID/GSK Ebola vaccine and an experimental Ebola vaccine developed by the Public Health Agency of Canada and licensed to NewLink Genetics Corporation. Other trials are to launch in the fall.
The trials are conducted in healthy adults who are not infected with Ebola virus to determine if the vaccine is safe and induces an adequate immune response.
In parallel, NIH has partnered with a British-based international consortium that includes the Wellcome Trust and Britain’s Medical Research Council and Department for International Development to test the NIAID/GSK vaccine candidate among healthy volunteers in the United Kingdom and in the West African countries of Gambia (after approval from the relevant authorities) and Mali.
Additionally, the U.S. Centers for Disease Control and Prevention has begun discussions with Ministry of Health officials in Nigeria about the prospects for conducting a Phase 1 safety study of the vaccine among healthy adults in that country.
Current Outbreak Prompted Accelerated Testing
The pace of human safety testing for experimental Ebola vaccines has been expedited in response to the ongoing Ebola virus outbreak in West Africa. According to the World Health Organization, more than 1,500 suspected and confirmed deaths from Ebola infection have been reported in Guinea, Liberia, Nigeria and Sierra Leone since the outbreak was first reported in March 2014.
“There is an urgent need for a protective Ebola vaccine, and it is important to establish that a vaccine is safe and spurs the immune system to react in a way necessary to protect against infection,” said the NIAID director, Dr. Anthony S. Fauci. “The NIH is playing a key role in accelerating the development and testing of investigational Ebola vaccines.”
He added that “we know the best way to prevent the spread of Ebola infection is through public health measures, including good infection control practices, isolation, contact tracing, quarantine and provision of personal protective equipment. However, a vaccine will ultimately be an important tool in the prevention effort. The launch of Phase 1 Ebola vaccine studies is the first step in a long process.”
Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, has stated that “tried and true public health interventions, strong supportive medical care and the rapid testing of Ebola vaccines and antiviral treatments can help to reduce suffering now and in the future.”
The investigational vaccine now entering Phase 1 trials was designed by Nancy J. Sullivan, chief of the Biodefense Research Section in NIAID’s Vaccine Research Center (VRC). She worked in collaboration with researchers at the VRC, the U.S. Army Medical Research Institute of Infectious Diseases, and Okairos, a Swiss-Italian biotechnology company acquired by GSK in 2013.
Clinical trials are a multistage process:
- In Phase 1, researchers test an investigational vaccine in a small group of people to evaluate its safety and the immune response it provokes.
- Phase 2 clinical trials of investigational vaccines are designed to further assess safety and immune response in larger numbers of volunteers. Under certain circumstances, a vaccine’s ability to prevent infection or disease (called efficacy) can be determined in a Phase 2 trial.
- Phase 3 clinical trials are directed predominantly at determining efficacy.
“The experimental NIAID/GSK vaccine performed extremely well in protecting nonhuman primates from Ebola infection,” Fauci said.
Safety features built into the study’s design include daily and weekly reviews of patient data by clinical staff and the study protocol team, as well as a staged enrollment plan that requires interim safety reviews after three participants have been vaccinated and have undergone three days of follow-up before enrolling additional study participants into the group. Participants in both groups will be seen and evaluated by clinical staff nine times over a 48-week period.
Initial safety and immunogenicity data from the Phase 1 trials of the NIAID/GSK investigational Ebola vaccine are expected in late 2014.