Ebola: Clinical trials for a safe vaccine
A clinical phase I trial for a potential vaccine against the dreaded Ebola virus can now begin. The candidate vaccine has already successfully been tested in different animal models. The trial is supported by the German Center for Infection Research (DZIF).
“The Paul-Ehrlich-Institut has given its approval, so we can now start the clinical trial,” Professor Marylyn Addo explains. The infectologist, who works for the DZIF at the University Medical Center Hamburg Eppendorf (UKE), will be leading the trial. The DZIF, the Clinical Trial Centre CTC North at the UKE and Prof Stephan Becker, Director of the Institute of Virology at the University of Marburg and Coordinator of the DZIF Thematic Translational Unit “Emerging Infections”, are collaborating closely to plan and oversee the trial.
30 voluntary trial subjects – healthy adults – will be administered the vaccine at CTC North at the UKE. “We will be testing the safety and tolerability of the vaccine in humans,” Addo explains. Besides this, the trial will also provide first insights into the kind of immune reaction the vaccine triggers. This is a crucial step in the fight against Ebola, as there have been no safe vaccines available to stop the spread of the virus to date.
The German Center for Infection Research supported the trial preparations and provided start-up funding, and the Federal Ministry of Health (BMG) and the British Wellcome Trust are providing further financial support for preparing and conducting the clinical trial. With this, they are jointly focusing on the dramatic Ebola epidemic in West Africa. For the trial preparations, DZIF researchers worked closely with the Paul-Ehrlich-Institut (PEI), which is supporting the DZIF as a partner for exploring new vaccine platforms.
Becker and Addo’s research teams are members of the recently established WHO led expert consortium (VEBCON), which aims to rapidly coordinate clinical vaccine testing in Africa. The WHO is providing the candidate vaccine.
The candidate vaccine being used in the trial is an attenuated, genetically modified vesicular stomatitis virus (VSV), which carries an Ebola virus surface protein. The immune systems of the vaccinated trial subjects are expected to create antibodies against this protein, which in the event of exposure to the Ebola virus help to prevent the disease from occurring. Preclinical trial results of the candidate vaccine rVSV- ZEBOV are promising: Vaccine protection develops rapidly after the administration of a single dose, and is also potentially effective immediately after an Ebola infection. In several non-clinical trials, the vaccines protected laboratory animals from the deadly Ebola virus.
“In the longer term, a vaccine against Ebola would be a blessing for people in the affected areas,” Becker stresses. “Within a few months after the start of the trial, we expect to have collected all the necessary data we need to assess whether we can expand and continue with the clinical development, and then people in the epidemic regions can also be vaccinated,” the virologist adds. Since the Ebola epidemic outbreak in December, over 5000 people have already died of the virus in the affected West African countries—Sierra Leone, Nigeria, Liberia, Guinea.
