Search Result For immune
The day of a successful vaccination – level 1
14-05-1796Smallpox is a very dangerous illness. It kills people. Cowpox is...
The day of a successful vaccination – level 2
14-05-1796Smallpox was a very dangerous disease which killed millions of people....
The day of a successful vaccination – level 3
14-05-1796Smallpox was a deadly and highly infectious disease that had killed...
