– Ebola vaccine trials under way in Mali (The Guardian, Oct 10, 2014):
Health workers in Mali have been given an experimental vaccine against Ebola designed to boost the immunity of those on the frontline of the battle against the disease, which has so far claimed more than 3,800 lives in west Africa.
Mali has no Ebola cases but it borders Guinea, where the outbreak began. The trials are taking place to determine whether the potential vaccine is safe and that it does at least have some sort of protective effect.
It is particularly important to test its effects on health workers, who in Guinea, Sierra Leone and Liberia are at the sharp end of the battle against the virus.
Safety trials began at Oxford University and in the US a couple of weeks ago. The healthy people who volunteered have so far shown no ill effects, so the trials have moved into Africa itself.
“This research will give us crucial information about whether the vaccine is safe, well-tolerated and capable of stimulating adequate immune responses in the highest priority target population – healthcare workers in west Africa,” said Prof Myron Levine, director of the centre for vaccine development at the University of Maryland, which is running the trial in conjunction with the Malian ministry of health.
“If it works, in the foreseeable future it could help alter the dynamic of this epidemic by interrupting transmission to healthcare and other exposed frontline workers.”
At this point, the researchers hope to establish that there are no significant ill effects, beyond perhaps a temporarily sore arm. But they will also be testing blood samples of the volunteers to ensure there is an antibody response, which is the signal that the vaccine may teach the immune system to recognise the virus and fight it off. Until it is used in health workers treating people with Ebola, however, there will be no real proof that it works.
The trials are proceeding with unprecedented speed with the cooperation of a large number of international organisations and governments, in the hope of having something available that is at least partially protective before the end of the year.
Health workers, who are desperately needed on the Ebola frontline, have been worst hit by the disease because they are in close physical contact with sick patients. There are not enough protective suits, particularly in remote areas, and there are risks of coming into contact with the virus when the suit is taken off, unless it has been thoroughly disinfected while still worn.
Three health workers in Mali have so far been vaccinated and 37 more will follow in the next few weeks. The vaccine is delivered by a cold virus, which does not cause any illness but delivers a single Ebola virus protein that is harmless by itself but can teach the immune system to recognise and respond to the whole virus in the future.
The vaccine has been designed by the vaccine research centre of the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland. It is being manufactured by the British drug company GlaxoSmithKline and the funding is partly from the Wellcome Trust in the UK.