No experimental vaccine has ever been on a faster track to clinical evaluation. The exceptional circumstances pose unique challenges. The scientific community must form new partnerships and coordinate its actions to accelerate research and avoid duplication of efforts. The public health community must weigh ethical issues and the principal of precaution against the imperative to get an Ebola vaccine out to the healthcare workers and populations on the front lines as quickly as possible. Beyond funding for research, vaccine manufacturers are confronted with the issue of scaling up production to be ready to rapidly meet demand should their vaccine candidate succeed in clinical trials. Who should support these risks?
The meeting reviewed the status of Ebola vaccine research, including the latest safety and immunogenicity data on the two candidate vaccines in phase I and II clinical trials. As phase III efficacy trials are about to commence, participants identified the challenges faced by vaccine researchers. They looked in particular at the issue of study design, comparing the approach taken in the three countries that are currently affected. In the face of an unprecedented epidemic, vaccine development must be compressed from a typical 5-7 years to just 12-18 months.
“What if we can’t demonstrate efficacy?” was an important concern voiced by researchers. It was unanimously agreed that it is essential to collect enough clinical data on the vaccine’s efficacy and safety before the epidemic subsides. Participants felt that, due to the urgency and short timeframe, phase II and III clinical trials should be conducted in parallel rather than sequentially. They also commended the regulatory authorities for adapting their approach to the crisis and enabling researchers to advance more quickly with preliminary data based on a risk-benefit assessment.
The group looked at the sociocultural and ethical challenges inherent in vaccine research. Médecins Sans Frontières shared the lessons learned from past Ebola outbreaks and their impact on their current response. Involving the community in outbreak control is a key success factor.
Participating experts agreed that, while the vaccine will not be the “magic bullet” that will resolve the current epidemic, it will be an indispensable tool to limit the spread of future outbreaks.