Human trial of experimental Ebola vaccine begins this week

(CNN) -- A highly anticipated test of an experimental Ebola vaccine will begin this week at the National Institutes of Health, amid mounting anxiety about the spread of the deadly virus in West Africa.

After an expedited review by the U.S. Food and Drug Administration, researchers were given the green light to begin what's called a human safety trial, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

It will be the first test of this type of Ebola vaccine in humans.

The experimental vaccine, developed by the pharmaceutical company GlaxoSmithKline and the NIAID, will first be given to three healthy human volunteers to see if they suffer any adverse effects. If deemed safe, it will then be given to another small group of volunteers, aged 18 to 50, to see if it produces a strong immune response to the virus. All will be monitored closely for side effects.

The vaccine will be administered to volunteers by an injection in the deltoid muscle of their arm, first in a lower dose, then later in a higher dose after the safety of the vaccine has been determined.

Some of the preclinical studies that are normally done on these types of vaccines were waived by the FDA during the expedited review, Fauci said, so "we want to take extra special care that we go slowly with the dosing."

The vaccine did extremely well in earlier trials with chimpanzees, Fauci said. He noted that the method being used to prompt an immune response to Ebola cannot cause a healthy individual to become infected with the virus.

Still, he said, "I have been fooled enough in my many years of experience... you really can't predict what you will see (in humans)."

According to the NIH, the vaccine will also be tested on healthy volunteers in the United Kingdom, Gambia and Mali, once details are finalized with health officials in those countries.

Trials cannot currently be done in the four countries affected by the recent outbreak -- Guinea, Sierra Leone, Liberia and Nigeria -- because the existing health care infrastructure wouldn't support them, Fauci said. Gambia and Mali were selected because the NIH has "long-standing collaborative relationships" with researchers in those countries.

According to the NIH, officials from the Centers for Disease Control and Prevention are also in talks with health officials from Nigeria about conducting part of the safety trial there.

Funding from an international consortium formed to fight Ebola will enable GlaxoSmithKline to begin manufacturing up to 10,000 additional doses of the vaccine while clinical trials are ongoing, the pharmaceutical company said in a statement. These doses would be made available if the World Health Organization decides to allow emergency immunizations in high-risk communities.

The GSK/NIAID vaccine is one of two leading candidate vaccines. The other was developed by the Public Health Agency of Canada and licensed this month to NewLink Genetics, a company based in Iowa.

According to the NIH, safety trials of that vaccine will start this fall.