The Department of Health has appointed an acting Chief Medical Officer (CMO) for England.

Professor Dame Sally Davies will take over from Sir Liam Donaldson on 31 May and will stay in post until a new CMO is appointed.

An 'open competition' to appoint a new Chief Medical Officer will be held this summer, according to the Department of Health.

Dame Sally comes from a research background. She was Director General of R&D and Chief Scientific Adviser for the Department of Health and NHS.

Sir Liam Donaldson announced his retirement in December after 12 years in post, making him among the longest-serving CMOs, Pulse magazine reports.

He had originally planned to leave in mid-2009 when he was 60, but agreed to stay in post to supervise the Government's response to the swine flu pandemic, according to Healthcare Republic.