REFILE-Scientists' path to usable Zika vaccine strewn with hurdles
(Refiles to fix typo in eighth paragraph)
* More companies join Zika vaccine development race
* Safe shot for at-risk women and girls a big challenge
* Full regulatory approval of vaccine will take years
* Commercial opportunity for Zika vaccine uncertain
By Kate Kelland and Ben Hirschler
LONDON, Feb 2 (Reuters) - The world is once again asking scientists and drugmakers to come up rapidly with a vaccine for a viral disease that, in the latest case, few people had heard of until a few weeks ago, and even fewer feared.
Making a shot to generate an immune response against Zika virus, which is sweeping through the Americas, shouldn't be too hard in theory. However, producing a safe, effective and deliverable product to protect women and girls who are at risk is not easy in practice.
For a start, scientists around the world know even less about Zika than they did about the Ebola virus that caused an unprecedented epidemic in West Africa last year. Continuación...