August 26, 2015 – Ebola Vaccine


Anchor lead:  An effective and safe vaccine for Ebola is here, Elizabeth Tracey reports

A vaccine with 100% effectiveness in preventing Ebola virus infection has been reported in the Lancet.  Mike Klag, dean of the Johns Hopkins Bloomberg School of Public Health, describes the study.

Klag: It was a very innovative trial.  It used an innovative strategy where they randomized by cluster.  These were clusters of index cases and contacts.  Everybody got the vaccine, but the randomization was to early versus late.   :14

About half of the 7500 people enrolled got the vaccine immediately, while the other half waited three weeks.  Klag explains the ethics of this design.

Klag: There is this concept of clinical equipoise.  For a trial to be ethical there has to be substantial uncertainty about whether the treatment is better than no treatment. This was a case where there was incredible uncertainty.  We didn’t know what the side effects would be.  We did not know how effective it would be. There was lots of uncertainty, but there’s not much uncertainty now.   :20

At Johns Hopkins, I’m Elizabeth Tracey.