Doctors and nurses are finally volunteering to fight the Ebola virus in West Africa after a long period of paralyzing fear in which almost none stepped forward.

But, experts say, even though money is now pouring in from the World Bank, the Gates Foundation and elsewhere, and the United States Army is to start erecting field hospitals soon, there is likely to be a long gap before those hospitals can be fully staffed to care for the growing numbers of people with Ebola.

“As a result, thousands of people will die,” said Dr. Joanne Liu, president of Doctors Without Borders, which treats more patients than any other entity. “I can’t say the exact figure because we don’t know how many unreported cases there are. But thousands for sure.”

Because months went by this summer in which almost no volunteers could be found, and because it takes time to train them and get them to Africa, there remains a yawning gap between the number of medical professionals needed and those in place to do the work. Each 100-bed hospital needs a staff of 400, about 40 of whom are foreign doctors or nurses. Meanwhile, about 600 Ebola cases are being recorded every week, according to the World Health Organization, and that number doubles every three weeks.