The chief medical officer has become the public face of swine flu and is largely responsible for the NHS and government’s response to it, including the purchase of tens of millions of doses of vaccine and Tamiflu.

If that turns out to be money well spent he will be the hero of the hour.

Professor Sir Liam Donaldson tends to plough a lonely furrow on many public health issues - but wins wars rather than battles. He was an advocate of stiffer tobacco control long before the government introduced a ban on smoking in the workplace; he has called for higher taxes on alcohol - initially dismissed by Gordon Brown but now getting support from across the political spectrum; and his views on donor organs are gaining more acceptance. The press may view him as either a nanny or a Cassandra: but it is just possible he is simply very far sighted.

He has pushed patient safety and quality issues during his 11 years at the top. He is a former regional director and has spent time in general practice, giving him an acute awareness of health inequalities.