Emergencies preparedness, response

Handling and synthesis of variola virus DNA

The scientific community must be fully aware that the distribution, synthesis and handling of variola virus DNA is governed by a series of recommendations developed initially by the WHO Ad Hoc Committee on Orthopoxvirus Infections in (1994) and updated by the WHO Advisory Committee on Variola Virus Research.

These recommendations, endorsed by the World Health Assembly, are to prevent the reconstruction of variola virus or the construction of a virus which will cause a disease with the same attributes as smallpox, either through the reactivation of variola virus DNA or the incorporation of variola virus DNA sequences into other orthopoxviruses.

An appropriate research laboratory may submit a formal request to the WHO Secretariat. Only upon approval of this request, can the variola virus DNA fragments be obtained from either one of the two WHO Collaborating Centres, acting as international repositories for variola virus. Scientists should be aware that the amount of DNA they request or hold must not exceed 20% of the total variola virus genome.

The full recommendations are available here: