The World Health Organization said it will have Ebola vaccines ready to give to hundreds of thousands of West Africans by the middle of next year, Reuters reports. Right now, there's no approved vaccine for Ebola. Researchers worked on vaccines before, but trials stalled because the disease is rare and because it mostly afflicts poor countries, so companies haven't been motivated to complete trials.

WHO is now considering two vaccines that have started testing in humans, plus five additional vaccines that aren't yet ready for human trials. Typically, clinical trials of experimental vaccines and drugs take years to conduct, but drug companies and other groups are trying to figure out how to get these vaccines through faster.

A vaccine alone won't end the epidemic in West Africa, but WHO thinks it could "turn the tide," Reuters reports. Marie-Paule Kieny, the assistant director general for health systems and innovation at WHO, has volunteered for vaccine trials herself, Science reports.