Because the vaccine may not stop transmission of the virus.

There are several ways in which it can and studies suggest they could be safe and effective.

NHS budgets, third world debt, predictions of global warming, inflation, Iraqi war dead, the decline of fish stocks or hedgehogs, the threat of cancer — there's hardly a subject people care about that comes without measurements, forecasts, rankings, statistics, targets, numbers of every variety. Do…

Cognitive biases shape how we understand data. Being aware of them gives us a better chance of avoiding bias.

The second part of this article looks at reducing students's contacts and face-to-face teaching.

We are proud to present the winners of the Plus New Writers Award 2009. The winners were chosen by our three prominent judges for each of the three categories — schools, university and general public. Read the winning entries now!