Ebola booster vaccine trial to combine GSK, Emergent Bio shots

LONDON (Reuters) - Scientists are to test a new two-shot Ebola vaccine using an experimental shot from Britain's GlaxoSmithKline, which is already in clinical trials in Africa, and a new kind of booster from Emergent BioSolutions. The Maryland-based biotech company said on Monday its modified vaccinia Ankara (MVA) Ebola Zaire vaccine would be used in an initial Phase I clinical study to be conducted by researchers at the University of Oxford. Although Ebola case numbers have fallen to a low level, drug companies are still pushing ahead with efforts to develop an effective vaccine, which may help fight the next outbreak, even if it does not come in time for the current epidemic. One big area of debate is whether it is better to have a single or double-shot vaccine. Administering a follow-up booster would almost certainly give greater protection but it would also make immunisation far more complicated. Currently, Denmark's Bavarian Nordic, which is working with Johnson & Johnson, has the most advanced MVA booster vaccine, which has also been tested in a small trial with GSK's shot. However, Bavarian's booster component needs to be grown in chicken eggs, which makes production difficult, while Emergent's cell-based vaccine does away with the need for eggs.