How effective are emergency vaccines during outbreaks?

Doctors Without Borders (also known by its French acronym MSF) staff disinfecting body bags containing deceased Ebola patients with chlorine before they are incinerated in a crematorium during the 2014 outbreak in West Africa. This was before the Ebola vaccine was available. — MSF filepic

Emergency vaccination during outbreaks of diseases like cholera, Ebola and measles have over the past quarter-century reduced deaths from such illnesses by nearly 60%, according to a new study.

A similar number of infections are also believed to have been prevented, while billions of euros have been generated in estimated economic benefit.