PLEASE HELP!!
How is smallpox different when it comes to making a vaccine?

"The smallpox vaccine does not contain smallpox virus and cannot spread or cause smallpox. However, the vaccine does contain another virus called vaccinia which is live in the vaccine. Because the virus is alive, it can spread to other parts of the body or to other people from the vaccine site."

[Copy and pasted from a medical website]

one centimetre is equal to 0.01 metres

this is a good question! i'll do some research and come back when i have the answer!