Adults who have never had chickenpox should get the same number of shots as teens. It is an illness caused by the varicella-zoster virus. A virus is a kind of germ that can make people sick. People with chickenpox get an itchy rash or spots on their skin. The spots are like small water blisters.
Some people have only a few blisters.
Others can have as many as 500. These blisters dry up and form scabs in 4 or 5 days. Chickenpox spreads very quickly. You can get chickenpox if you touch a blister, or the liquid from a blister. You can also get chickenpox if you touch the spit of a person who has chickenpox.