Ebola vaccines left hanging as GSK, Merck, J&J scramble for trial volunteers

The race for an Ebola vaccine has slowed to a crawl as Big Pharmas GlaxoSmithKline ($GSK), Merck ($MRK) and Johnson & Johnson ($JNJ) struggle to find volunteers who are exposed to enough disease to show whether experimental vaccines actually protect against Ebola infection.

As the number of reported Ebola cases dwindled, concern that the companies would not be able to test their vaccines' effectiveness against Ebola disease grew. Now, the only country where new Ebola cases are still being reported is Guinea, Reuters reported on Wednesday. Researchers consider it the "only hope" to prove efficacy and cross the finish line on an Ebola vaccine.

"There's no doubt everybody is very happy we have so few Ebola cases, but obviously it's also a bit disappointing when there was so much effort and energy put into accelerating the vaccines that there are suddenly no cases for the trials," said the World Health Organization's Marie-Paule Kieny, as quoted by Reuters.

Glaxo and Merck took their vaccines to Phase II trials in Liberia, testing them on more than 600 people. The companies reported positive results in April. They planned to enroll more volunteers to consolidate the Phase II data and to enroll more than 27,000 volunteers for a Phase III trial. But, according to Reuters, the Phase III trial had to stop enrolling after reaching its midstage target: 1,500 patients.

As for J&J, the pharma initially planned to conduct a 350,000-patient trial, but had to cut back to 3,000 to 4,000 for a midstage trial in Sierra Leone.

In the early days of the epidemic, Big Pharmas and smaller biotechs alike recognized the urgent need for a vaccine. While the industry's response to the most recent Ebola epidemic was rapid and encouraging, the current lull emphasizes the need to act even more quickly when developing vaccines for emerging diseases.

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