In the News Review article “Bioweapons: Delivering death in the mail” (Nature 414, 837–838; 2001), you quote Stanford biophysicist Steven Block as opposing restrictions on access to bioweapons agents, endorsing having “a lot of terrific [biomedical] scientists working on the problem” and forecasting “a 'molecular arms race' between bioweapons developers and biodefence specialists”.

We believe that increasing the number of institutions and people with access to bioweapons agents will increase the likelihood of their release. We find the idea of a government-sponsored, large-scale multi-site “molecular arms race” frightening, and likely to lead to disaster. (See also Opinion and News, Nature 414, 235; 2001 and Nature 414, 237–238; 2001.)

We recommend a moratorium on new permits for possession or transfer of bioweapons agents until the following measures are put in place: national or regional limits on numbers of laboratories permitted access to bioweapons agents; minimal containment requirements (BL-3); minimal security requirements (video surveillance, entry guards, dual-key locks, personnel screening; requirement that two people should be present during any work); inventory-reporting procedures; and inspection and review procedures.

We believe that all laboratories without current permits, and/or not in compliance with the requirements above, should be required to transfer (under special permit) or destroy stored bioweapons agents.

This scheme would restrict access to bioweapons agents, but would not, in our view, unduly restrict biodefence-related research. Research in laboratories without access to bioweapons agents could be performed using non-pathogenic or moderately pathogenic species as simulants (for example using Bacillus subtilis, B. thuringiensis or B. cereus as simulants for B. anthracis), and/or through collaboration with laboratories permitted access.

This scheme is more restrictive than current official proposals. However, we believe that it represents the minimum required to provide a real increase in security. The National Institutes of Health has announced a major funding initiative for biodefence research. Without new restrictions, this initiative is likely to increase the number of institutions and people with access to bioweapons agents, and with training in production, handling and modification of these agents — and thus, perversely, to make us less secure.