Sir

The recent outbreak of foot-and-mouth virus around the Pirbright animal-health laboratory in Surrey should dissuade the UK Medical Research Council from pursuing plans to move the National Institute for Medical Research (NIMR) from its semi-rural campus to the centre of London.

The expertise and facilities of the NIMR, which are among the world's best, are vital to combat future infectious diseases, and are a key component of national and international biosecurity. Research carried out at the NIMR includes studies on emerging pandemic viruses, such as avian influenza (H5N1), which are grown in level-4 containment facilities.

The NIMR has a superb safety record. However, the recent crisis at Pirbright is a reminder that accidents happen. The current Mill Hill site is excellent for minimizing secondary risk. If the NIMR is moved to central London, the consequences of containment failure would be horrific. A three-kilometre exclusion zone, as used in the recent foot-and-mouth epidemic, would reach 10 Downing Street and quarantine most of the UK government's decision-makers. A ten-kilometre surveillance zone would affect all of central London.

Kings Cross, Euston and St Pancras railway stations, used by several million passengers each week, are five minutes' walk from the proposed NIMR site. After St Pancras becomes the London terminus for Eurostar in November, an escaped pathogen could reach Paris and Brussels within two hours. The first duty of government is security: the NIMR should stay at its present site.