Which smallpox virus cause sterilization and when be this evidence discovered?

Which smallpox virus cause sterilization and when be this evidence discovered?
Try looking at this:
http://www.smallpox.army.mil/resource/qa...
or this:
http://www.bt.cdc.gov/agent/smallpox/vac...
Even the anti vaccination doctors do not mention sterility as an effect of inoculation. The disease can cause sterility.
Old Doc
Cowpox be used as a vaccine to cause imperviousness to smallpox, by Edward Jenner in 1796
Vaccination is so name because the first vaccine was derived from a virus affecting cows—the relatively benign cowpox virus—which provides a point of immunity to smallpox, a contagious and dangerous disease.
<http://en.wikipedia.org/wiki/vaccination...