09/26/2014 09:12 EDT | Updated 11/26/2014 05:59 EST

Who: Thousands of doses of experimental Ebola vaccines should be ready in coming months

DAKAR, Senegal - The World Health Organization says there should be thousands of doses of experimental Ebola vaccines available in the coming months and they could eventually be given to health care workers and other people who have had contact with the sick.

But Marie-Paule Kieny, assistant director-general at WHO, cautioned reporters in Geneva on Friday that no vaccine has yet been proven safe or effective in humans. Testing has now begun to make sure they are not harmful to people.

A vaccine may then be put to use in this outbreak, but Kieny warned that until its effectiveness is proven, anyone receiving it would still have to operate as if they are not protected against Ebola.

The Ebola outbreak sweeping West Africa is believed to have killed more than 2,900 people.