MONROVIA, Liberia — Nearly a year after the Ebola virus first emerged in West Africa, officials have launched the first large-scale trials of two experimental vaccines in Liberia.
The trials, which began on Feb. 2, involve introducing vaccines to 12 volunteers in Liberia. Within the next year, 27,000 – 30,000 volunteers will be injected with either one of the two vaccines being tested or a placebo vaccine.
The British-based pharmaceutical company GlaxoSmithKline partnered with the U.S.-based National Institutes of Health to produce the first vaccine, which “uses a chimpanzee common cold virus to carry a single Ebola protein,” the BBC reports.
The Public Health Agency of Canada teamed with U.S.-based Merck, Inc. to produce the second vaccine, which uses a livestock virus to carry an Ebola gene.
While the Ebola strains in each vaccine are too weak to infect the volunteer with the virus, the hope is that each vaccine will trigger the production of productive antibodies against Ebola.
As of Feb. 1, there have been 22,444 cases of Ebola worldwide, with 8,959 deaths, according to the Centers for Disease Control and Prevention. Of those nearly 9,000 dead, 3,739 were Liberian patients.
Still, the number of new Ebola cases in West Africa is declining rapidly. During the last week in January, there were only four new reported cases in Liberia, according to the World Health Organization.
While Ebola’s decline is welcome news for world leaders, patients and the general population, it may pose obstacles for vaccine development, NPR reports.
“It’s very difficult conducting clinical trials when there are very few actual patients,” said Martin Friede, a World Health Organization program leader who coordinates Ebola drug development.
With fewer patients, the likelihood of being exposed to Ebola is diminished. If the volunteers in the Ebola vaccine trials are not then exposed to the virus, it is difficult to determine whether the vaccines are truly effective.
Nevertheless, many health experts contend that the Liberian vaccine trials are still worthwhile.
For instance, blood tests that determine immune system response can be taken from vaccine patients after the trial is complete. According to Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, if the immune response of the patient resembles the immune response of monkeys that have already tested positively to the vaccines, the vaccines may be approved on those grounds alone.
Alternatively, the vaccines could be further tested in Sierra Leone and Guinea, although additional vaccine trials come with extensive costs and complications.
For the present time, health professionals are beginning to consider drug preparation for the next Ebola epidemic, while containing the current one once and for all, NPR reports.
– Katrina Beedy
Sources: The Guardian, NPR, BBC, Centers for Desease Control and Prevention, BBC
Photo: Huffington Post