<unk>  is a contagious disease unique to humans.<unk>  is caused by either of two virus variants named Variola major and Variola minor. The deadlier form, V. major, has a mortality rate of 30–35%, while V. minor causes a milder form of disease called alastrim and kills ~1% of its victims. Long-term side-effects for survivors include the characteristic skin scars.  Occasional side effects include blindness due to corneal ulcerations and infertility in male survivors.
Smallpox
Cowpox
Chickenpox
Mumps
Rickettsialpox
Cat scratch fever
Polio
Tularemia