By Patrick McGroarty and Drew Hinshaw 

Global health experts are preparing to test new treatments for Ebola in West Africa that they hope will eventually vanquish the hemorrhagic fever.

The National Institutes of Health and GlaxoSmithKline PLC plan to test a vaccine among Liberian health workers. Similar rollouts are being discussed in Sierra Leone.

The World Health Organization hopes that work will yield a vaccine in 2015. But no one knows whether the treatment will prove safe and successful, or when it might be ready. Any vaccine would probably be given first to at-risk health workers, pharmaceutical company representatives say, meaning its role ending the broader epidemic would be limited.

Separately, the Bill & Melinda Gates Foundation and other groups are testing whether the antibody-rich blood of people who have survived Ebola can help new patients fight off the virus. Those small, complex tests will also take time to execute and review.

Meanwhile, Ebola is still spreading to new communities, though the rate of new infections is falling. Stamping out Ebola in the far-flung villages where it is appearing now could be more difficult than stopping the wave of cases that overwhelmed weak health systems from July through October. How rapidly the response evolves to tackle that shifting foe will help determine how high the death toll climbs in 2015, health experts say.

A closed Liberian shirt factory speaks to Ebola's economic impact--and why there won't be a quick economic recovery in 2015 despite the push for new treatments.

In Monrovia's crowded West Point neighborhood, Chid Liberty, owner of garment maker Liberty & Justice, had hoped to take advantage of a duty-free export arrangement with the U.S. He hired 300 women last year to make shirts and pants in a refurbished warehouse in the capital. But there is no production and no U.S. exports. The sewing machines have gone quiet.

"It's all on pause," he said.

Liberia, Guinea and Sierra Leone were finally experiencing a turnaround from decades of conflict and political tumult when Ebola interrupted. Now the countries are likely to tip into recession in 2015, the World Bank and government leaders say, the consequence of an epidemic that has killed nearly 8,000 people in those three hardest-hit countries.

The number of people threatened by hunger in those countries could double to one million by March if food supplies don't improve, two United Nations agencies warned in December.

"As long as the epidemic continues, the human and economic impact will only grow more devastating," World Bank President Jim Yong Kim said when he visited the region in December.

At the same time, drawing back investors is also crucial, leaders from the three countries say. So is resuming work on road, water and power projects that could help raise living standards.

"All of those have been put on hold," Liberian President Ellen Johnson Sirleaf said in a November interview. "It is truly devastating."

Declines in the prices of iron ore and oil also herald a slow recovery for Liberia, Guinea and Sierra Leone, countries looking forward to revenue from promising mining projects and oil reserves off their coasts.

When Ebola arrived in West Point in July, followed by soldiers who barricaded the neighborhood, commerce in Monrovia evaporated. Mr. Liberty flew to Chicago, his adopted home. His employees, many of whom were using their wages to send their children to school for the first time since Liberia's 14-year civil war ended in 2003, were sent home.

On a recent visit, a few sample pairs of pants sat in plastic bags in a corner. They were meant to be the first Liberia-made trousers the company shipped to the U.S. The sewing machines used to make them were covered in dust.

Write to Patrick McGroarty at patrick.mcgroarty@wsj.com and Drew Hinshaw at drew.hinshaw@wsj.com

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