The incubation period of smallpox is 7-17 days.
The pox are caused by Orthopoxviren, known as the pox viruses.
It is a very serious infectious disease.
The smallpox virus is spread by droplet infection and by contact.
Since 1977, no more cases of smallpox occurred. The last case in Germany in 1972 occurred.
The Pokenvius probably exist only in labs. It would not be excluded that this as a biological weapon could be used.

Smallpox incubation period: 7-17 days