We are now one step closer to an Ebola virus vaccine, better late than never !


The two main promising vaccine " candidates " are " vectored " ( carried ) in other, harmless, viruses. Only part of the Ebola virus is thus carried - a surface protein which helps the virus enter " host " human ( or non-human primate ) cells. The hope is that this stimulates an immune response which stops the Ebola virus infection.


The vaccine in a small trial just completed in the USA is " bivalent " – acting against the current ( " Zaire " ) strain, and also the " Sudan " strain. It had already been shown to work in non-human primates. The trial only involved 20 healthy human volunteers. None of these suffered major side effects. There was an antibody response in all of them, and also other ( " T cell " ) responses.


Of course this was only a phase I trial, confirming an immune response. It needs a much larger trial involving healthcare workers, burial workers and others in close proximity to people with Ebola disease. This would hopefully confirm a lasting, protective, immune response - and no major side effects. Other similar trials are under way elsewhere, including Oxford, Switzerland and Mali.


There is little " good news " about the Ebola virus disease crisis. One is the stimulus to look for new treatments and vaccines. Things are moving faster than usual when evaluating such developments, because this is a humanitarian crisis. It doesn’t mean that trials of prevention or treatment of other illnesses could - or should - be as rapid. There are all sorts of considerations like cost, effectiveness, and side effects which would normally favour more caution and patience.


There are reasons to be cheerful that this battle for control within West Africa, and then protection, CAN be achieved next year. All the other problems - both health-related ( TB, malaria, malnutrition ) and economic, facing this part of Africa, may well not be solved so rapidly.


http://www.nejm.org/doi/full/10.1056/NEJMe1414305