Emotions still run high over the stocks of smallpox virus placed into the P4 freezers of Atlanta and Novosibirsk more than 30 years ago by the World Health Organization. In this week's BMJ, two articles present opposing views on whether the United States and Russia should destroy their stocks of smallpox virus (Variola).1 2

One argument for maintaining smallpox stocks is that they are needed to develop safer vaccines.1 Our current effective vaccine is safe when used judiciously—not for mass vaccination of populations, but for targeting those at risk after screening out people with a history of HIV, leukaemia, or eczema at higher risk of complications after vaccination.3 Moreover, new vaccines are based on Vaccinia, not smallpox.4 No new vaccine can be tested for efficacy until human cases of smallpox reappear.

Another argument is that smallpox stocks are needed to assess antiviral agents for the treatment of smallpox. Again, no agent can be properly tested until human cases reappear. …