Virus Home > Smallpox Incubation Period
A Summary of the Smallpox Incubation Period
When a person becomes infected with the virus that causes smallpox (variola), the virus begins to multiply within the body. After approximately 12 to 14 days, smallpox symptoms can begin (symptoms can begin as early as 7 days or as late as 17 days). This period between the transmission of smallpox and the start of smallpox symptoms is the "smallpox incubation period."