Each step forward, however, is often accompanied by a glance, or even a half-step, back.

ECONOMIST: Room for improvement

It looks like they've struck a sweet spot with performance and have taken a bit step forward as they usually do in the second half of the season.

BBC: David Coulthard column

The malaria vaccine is far from perfect, protecting close to half of its recipients from the disease, but it is nevertheless a huge step forward in combating malaria across a continent that needs all the help it can get.

FORBES: Science and Skepticism: Malaria Vaccine Successful in Trial Run