The first batch of Ebola vaccines was shipped to Liberia on Friday, Jan. 23. Vaccine developer GlaxoSmithKline expects to eventually send 30,000 Ebola vaccines. The first clinical trials will be on people with the most risk of developing the illness­-frontline health workers.

"They've passed all the quality checks and now can be sent to the site," GlaxoSmithKline vice president Dr. Rip Ballou told NBC News.

The vaccines will be produced by Okairos, a Swiss-Italian biotech company purchased by Glaxo, and NewLink Genetics, a Canadian health company licensed by Merck.

More than 21,000 people have contracted the disease in Liberia, Sierra Leone and Guinea, and 8,600 of them have died.

"This is an unprecedented epidemic," Ballou said. "It is a highly populated part of Africa. It is an economically important part of Africa. If it were to spread into surrounding countries -- think about Nigeria, the most populous nation in Africa."

The vaccine was tested previously on 200 healthy volunteers in the U.S., U.K., Switzerland and Mali.

The epidemic hastened the development and approvals by health regulators. While new drugs and vaccines follow a three-step testing process, the new vaccine has by-passed two rounds of smaller trials and will go to the final phase of testing on the most affected.

Even with the unparalleled acceleration, the manufacturers still face hurdles. The World Health Organization and other regulators must be satisfied with the vaccine's safety and effectiveness before mass immunization is conducted. Storage of the vaccines will also be a challenge since they must be stored in temperatures colder than most freezers can produce.

Dr. Moncef Slaoui, of GlaxoSmithKline, told the BBC News, "Shipping the vaccine today is a major achievement and shows that we remain on track with the accelerated development of our candidate Ebola vaccine.