25 years since the eradication of smallpox: why poxvirus research is still relevant.

The World Health Organization (WHO) announced the eradication of smallpox twenty-five years ago this month. This conquest of an infectious disease, which has been the bane of humankind for centuries, still stands as the WHO's greatest achievement. The anniversary of such a scientific and medical landmark provides an appropriate occasion to reflect on this feat and to assess the significance and necessity of the poxvirus research that has followed this.