
Cover image: Statue of Shapona, the West African god of smallpox, from the Centers for Disease Control and Prevention (CDC) Global Health Odyssey collection. The large, slowly evolving genome of the variola virus, the agent of smallpox, enabled the authors to reconstruct the history of its evolution. See the article by Li et al. on pages 15787–15792. Photo by James Gathany, courtesy of the CDC Public Health Image Library.