Under scrutiny: Smallpox vaccine recommendations

The eradication of smallpox is widely considered to be one of the great achievements of public health. However, international terrorism in the US and elsewhere has led to increasing concern about vulnerability to a smallpox bioterror attack. Timely vaccination is highly protective against smallpox but carries risks of morbidity and mortality. Significant debate has therefore emerged regarding the optimal strategy for defence. In principle, there are three options: either mass or limited vaccination prior to an attack; quarantine and vaccination of all suspected cases of smallpox following an attack with isolation and vaccination of potential case contacts; and mass vaccination after the identification of a case of smallpox. This paper reviews smallpox disease, smallpox vaccination and the development of current smallpox vaccination policy in the US. Mathematical models of the spread of smallpox and control strategies are reviewed to explore specific smallpox vaccine policy considerations. Limitations of these models are considered and recommendations are made for future research.