January 23, 2015

Expert reaction to news of potential Ebola vaccine commencing phase 3 efficacy trials in Liberia

The first batch of a potential Ebola vaccine (from GSK) has been flown to Liberia to begin phase 3 efficacy trials. The trial is expected to involve up to 30,000 people.

Prof. Jonathan Ball, Professor of Molecular Virology, University of Nottingham, said:

“This is an important step for Ebolavirus vaccine development. In order to show that a vaccine works you have to perform phase III trials in those people most at risk from the infection.

“Make no mistake, this isn’t an easy task; there are huge logistical hurdles to overcome. Ebolavirus infection has decimated what was an already under-resourced Liberian healthcare infrastructure, making delivery a tricky thing to achieve. These vaccines also need cold storage, which isn’t always easy to guarantee. Also, recruitment to the trials will require a huge effort in social engagement and education.

“Ironically, the increased international effort that we saw towards the back-end of 2014 means that case numbers in all of the affected countries is falling – infection prevention and control really does work – and these decreasing numbers mean that it becomes increasingly more difficult to be able to determine whether or not the vaccines work. This is a crucial endpoint if these vaccines are to be available to help combat inevitable future outbreaks.”

Prof. Andrew Easton, Professor of Virology, University of Warwick, said:

“This is obviously a step forward in developing a preventative vaccine for Ebola virus. Assessing the efficacy of the vaccine may be more difficult now that the number of cases is reducing but nonetheless it marks a very positive move towards being able to reduce the impact of the virus. We will now wait to see the data that accumulates from the use of the vaccine in Liberia.”

Dr Jeremy Farrar, Director of the Wellcome Trust, said:

“This week we’ve heard encouraging news from West Africa, indicating that we may at last have reached a turning point in what has been the worst Ebola outbreak in history. Mali has been declared free from the disease and schools in Guinea reopened, restoring some sense of normality for those communities.

“But the disease continues to take a terrible toll elsewhere in the region, particularly in Sierra Leone. This is certainly not the time for the national and international efforts to be reduced, if anything efforts need to be redoubled to bring the epidemic to a complete end. Which is why it’s so important and heartening that the first doses of a potential vaccine are now making their way to west Africa in preparation for large scale trials. There is no doubt that we need vaccines and therapeutics for this epidemic and to try to prevent and respond to the inevitable future epidemics.

“The unprecedented speed at which the vaccine preparation has progressed would not have been possible without sheer determination and global partnership between national governments, funders, researchers and pharma companies, and agencies on the ground who have worked tirelessly to get this crisis under control.”

Declared interests
Dr Jeremy Farrar is Director of the Wellcome Trust, which is funding a trial of this vaccine in the UK and Mali and parallel studies of other vaccines in Geneva, Gabon, Kenya and Guinea.