In an article published in The Lancet, experts from an international Ebola research consortium known as the Partnership for Research on Ebola Vaccination (PREVAC) have assessed the current Ebola vaccine candidates across the world, and what remains to be achieved for viability.
PREVAC is currently undergoing Phase 2 clinical trials with three Ebola vaccination strategies for people one year and older. In all, the consortium states that 36 trials of Ebola vaccine candidates have been completed, with another 14 currently underway. Ebola remains a deadly public health threat, as an ongoing outbreak in the Democratic Republic of the Congo proves.
Currently, only one experimental vaccine comes with clinical efficacy data: rVSV-ZEBOV. That vaccine underwent a clinical trial in Guinea during the 2014-2016 Ebola outbreak there. That said, the authors of this study reviewed the status of four additional vaccine candidates and found that more data is needed concerning pregnant women, children and immunocompromised populations, as well as data that assess the durability and rapidity of immune responses caused by the vaccines.
By the authors’ conclusions, additional studies are needed to identify reliable measurements of the part of immune response which indicates a person’s immunity. Large-scale trials also must be conducted to determine the safety and effectiveness of these vaccines. Improved global capacity to conduct clinical research and form partnerships will be needed to make this a reality.
PREVAC consists of members from the National Institute of Allergy and Infectious Diseases (NIAID), as well as the French National Institute of Health and Medical Research (Inserm), the London School of Hygiene & Tropical Medicine (LSHTM) and the West African Clinical Research Consortium.