Two potential vaccines are now being tested for safety in people, and Russia is developing another one. While quantities will be limited, scientists say even a relatively small supply of vaccine can help bring the epidemic under control.

There’s no guarantee that any vaccine will be effective, so it’s good that several are in the pipeline. That includes an Ebola vaccine being developed by GlaxoSmithKline, which has already been tested in a small number of volunteers in the U.S., Europe and Africa.

Marie-Paule Kieny, Assistant Director-General for Health Systems and Innovation at the World Health Organization says a Canadian vaccine licensed to NewLink Genetics in Ames, Iowa, is now being tested in people as well at the Walter Reed Army Medical Center and the National Institutes of Health, near Washington D.C.