The Ebola epidemic that swept through Africa left 11,000 deaths in its wake, and now health experts and governments are using lessons learned from that crisis to fight the Zika virus in Latin America and the Caribbean.

"We saw Liberians were dying every day,” said Ebola survivor Naomi Tegbeh. “... and we don't want Liberians to go back to those days."

Experts don't expect Ebola to ever return to West Africa with such ferocity. Those countries now have laboratories, better hospitals and public health systems.

The slow response from donor countries and the World Health Organization, however, allowed Ebola to tear through Guinea, Liberia and Sierra Leone.

In contrast, the WHO has already called Zika an international emergency because of its possible link to birth defects.

FILE - Researcher Adrian Hill holds a vial of an
FILE - A vaccine against Ebola, developed by the Public Health Agency of Canada, proved effective in human trials. Drug companies are working to develop a Zika vaccine.

Prevention, vaccination, funding

Experts, however, say more needs to be done on a global scale. 

"We need to build the systems around the world to find things when they first emerge, to stop them rapidly, and to prevent them whenever that's possible," said Dr. Tom Frieden, head of the U.S. Centers for Disease Control.

Large pharmaceutical companies worked cooperatively to produce Ebola vaccines. Dr. Julie Gerberding, the president of Merck, said these companies need to be included — from the beginning — when a health crisis strikes.

"We are necessary,” she said. Nongovernmental organizations “cannot develop vaccines and manufacture them to the kind of scale that we need."

Drug companies are ready to start working on a Zika vaccine, and experts from the U.S. and other countries are working in Latin America to help find the cause of the virus's alarming link to birth defects.

However, funding is critical — not just for Zika or Ebola, but to combat any virus.

"We really do have to make sure that the world is safe, because the next time we may not be so fortunate as to have something we can contain,” said Georgetown University professor Lawrence Gostin. “We might have a novel influenza that will literally sweep the world and cause millions of deaths in its wake, and we can't allow that to happen."