U.S. pharmaceutical company Johnson & Johnson says it is accelerating clinical trials on an Ebola vaccine — one of a possible three being tested — as the death toll continues to climb in the world’s deadliest outbreak, according to a Euronews report.

Other fast-tracked vaccines being tested include one developed by British pharmaceutical company GlaxoSmithKline and the National Institutes of Health’s Institute of Allergy and Infectious Diseases. The first two doses of the experimental Ebola vaccine have been injected into human subjects, ABCNews reports.

Two other companies, Tekmira (Canada) and BioCryst Pharmaceuticals (North Carolina), have therapeutic candidates for Ebola in early development, funded by the U.S. Department of Defense’s Defense Threat Reduction Agency, according to the Centers For Disease Control in Atlanta. The Department of Defense is working with an Iowa-based company, Newlink, to develop an Ebola vaccine. BioCryst, with NIH support, is working to develop an antiviral drug to treat Ebola virus that is expected to begin Phase 1 testing later this year, the CDC reports.

Research efforts have been getting more publicity in the race to develop new drugs since the World Health Organisation ruled it is ethical to use experimental products on the virus based on the speed of its spread.

Experts will join the World Health Organisation today in Geneva to discuss Ebola vaccines, experimental treatments and how testing can be fast-tracked to help those who need it most, Euronews reports.

“This Ebola epidemic is the largest and most severe and most complex we have ever seen in the nearly 40-year history of this disease,” said Margaret Chan, director-general of the World Health Organisation at a Washington, D.C. news conference. “No one, even outbreak responders with experience dating back to 1976, to 1995, people that were directly involved with those outbreaks, none of them have ever seen anything like it.”

Ebola has claimed more than 1,900 lives in West Africa since March, Euronews reports.