By Adedayo Ogunleye, Abuja
A wave of relief may be sweeping through the world as scientists in the U.S have declared that the first batch of human trials of an experimental Ebola vaccine “has produced promising results”.
Scientists working at the National Institute of Health, NIH, have reported that all twenty healthy adults who received the experimental vaccine produced an immune response and developed anti-Ebola antibodies without any observable serious side effects except a couple of trial subjects who developed a brief fever within twenty-four hours of vaccination.
The vaccine project is a collaborative project between GlaxoSmithKline, the British pharmaceutical giant and the National Institute of Allergy and Infectious Diseases, NIAID, an arm of the NIH.
The director of NIAID, Anthony Fauci, said that the recent positive results have encouraged the research team to continue experimentation and to undertake even larger trials to determine how effective the vaccine really is.
“This response is very comparable to the level of the response that actually protected the animals,” he said.
The experiment involves isolation of two genetic strains of the Ebola virus from Sudan and Zaire. Isolated strains were extracted and delivered to participants via a harmless chimpanzee cold virus.
According to the NIH, two groups of volunteers ranging between ages eighteen to fifty were involved; one half received the vaccine via intramuscular injection at a lower dose and the other half a higher dose of the same vaccine. The blood of the volunteers were tested two weeks and again, four weeks after receiving the vaccine to establish whether the vaccine had induced production of anti-Ebola antibodies.
The researchers reported that all the volunteers developed the desired antibodies within four weeks of receiving the vaccine, and that those who had received higher doses of the experimental vaccine developed higher quantities of the antibodies.
The researchers also revealed that their experiments also sought to find out if the vaccine would catalyse production of T cells which are immune system cells since a previous study on primates with the same vaccine had showed that they may also help to protect from the disease; their hunch was confirmed as many of the volunteers produced the desired T cells and CD8 T cells, which, they suspect, play a crucial role in protection against Ebola infection.
Officials at the NIH have reassured the public that while the Zaire strain is responsible for the current outbreak, the vaccine under trial does not contain the Ebola virus and therefore cannot lead to Ebola infection in humans.
The NIAID has also acknowledged that because there is no ethical way to vaccinate people and then infect them with Ebola on purpose, the trial seeks only to ascertain safety of the vaccine and to discover if the immune system will respond in a defensive manner as expected.
They reported in the New England Journal of Medicine that their tests were successful as the immune system did respond in a protective manner.
For health workers, however, the litmus test will come only if and when doctors, nurses and other health workers have to rely on the vaccine for protection as they work in the field, treating Ebola patients.
The risk is enormous; reports from the World Health Organization,WHO, reveals that five hundred and eighty-eight health care workers have been infected with Ebola out of which three hundred and thirty-seven have died.
The Ebola epidemic continues to rage through Sierra Leone, Liberia and Guinea, infecting more than fifteen thousand people and killing five thousand of them. Experts have accelerated vaccine research and treatments for Ebola because of the epidemic, even though they know they won’t be able to use them any time soon to try to control it.
It is, however, the hope of many that the researchers would be able to make enough vaccine to at least protect health care workers fighting the epidemic.