WHO Advisory Committee on Variola Virus Research: report of the 11th meeting, Geneva, Switzerland, 4-5 November 2009

Overview

The major accomplishments in the WHO variola virus programme were as follows:

• WHO smallpox vaccine emergency stockpile of 32.6 million doses was established, well in excess of the original target of five million. Four individual Member States have pledged 27 million doses to be given in case of additional needs.
• In light of the 2011 review process on smallpox research, the Committee had agreed that it would produce a report based on a series of reviews and these would be submitted to an external committee that was independent of both WHO and its Advisory Committee for review. The Advisory Committee considered and discussed six preliminary reviews.
• The potential usefulness of wild-caught prairie dogs (Cynomys ludovicianus) as a model for human smallpox was investigated. Because of the lack of overt illness, the prairie dog was not considered to be a good animal model for variola virus infections.
• Work continues in investigating protein-based diagnostics and the development of point-of-care assays that are simple to use, stable, robust and easy to interpret.
• The potential reservoirs of, diagnostics for, and the epidemiology of cowpox virus infections in Germany was reported, but cases have been reported in other European countries as well. Human infections through zoonotic transmission have been documented. It is believed that rodents are the reservoir. It was noted that the cowpox virus infections in rats may be a promising model of orthopoxvirus pathogenesis.
• The Committee was presented with a comprehensive review of antiviral agents which have shown anti-variola virus activity (cidofovir, ST-246 and CMX001). These compounds have obtained Investigational New Drug (IND) status from the US Food and Drug Administration (FDA). The Committee recalled that capability to perform work with live variola virus must be maintained at least until two anti-variola drugs with different mechanisms of action have gained regulatory approval.
• The access and preservation of the WHO archives of the Smallpox Eradication Programme was discussed. Work is under way to convert all the materials into a digital format which will allow full text searching.
• The Committee reviewed the risks and benefits of vaccinating with smallpox vaccine health-care workers exposed to monkeypox. The Committee decided that vaccination of health-care workers should be given to HIV negative health-care workers because of the risks associated with exposure to monkeypox virus. Vaccination after an outbreak was detected would not provide time for screening for HIV and would be too slow to offer optimal protection.