Agreement will help push vaccine towards regulatory approval.

Guinea is having its first Ebola outbreak since 2016, when West Africa experienced the biggest outbreak ever seen. Could the vaccine that contained previous outbreaks soon be redeployed?

Guinea declares end of Ebola outbreak after 42 days without new cases. Outbreak resulted in 23 likely cases, 12 deaths since February. Success attributed to community buy-in, capacity building and vaccination.

The tracking of antibodies in Ebola survivors suggests they wax and wane, which could make vaccine booster shots necessary.

The virus is always present in nature and when circumstances allow, it may jump from one species to another.