Does the smallpox vaccine wear off?

Answer 1

The devil is in the details of exactly what you are referring to here. Do you mean: Can a person who has been vaccinated against smallpox then catch it at a later date, and while not getting sick from it, transmit it to others? Ans: In general, no. The vaccination not only keeps you healthy, but stops the virus in your body. Can a person who has recently been vaccinated against smallpox pass on smallpox to someone else? Ans: No, we don't use weakened variola virus (smallpox virus) to inoculate people. Can a person who has been recently vaccinated against smallpox using the standard live vaccinia virus type vaccine pass on a vaccinia virus infection to other people? Ans: Yes! And, it can be dangerous. That's why people should be careful with their fresh smallpox vaccination wounds. Can a person who has been recently vaccinated with the newest MVA-type smallpox vaccinations pass on a vaccinia infection on to others? Ans: No. At least theoretically not. But, it's so new, we can't say for absolute certain.

Answer 2

The smallpox vaccine loses much of its effectiveness after 3-5 years and continues to wear off there after. (Source was the cdc website)

Answer 3

There is zero chance of getting smallpox from a vaccine. There could be an adverse reaction to the vaccine serum such as high fever, anaphylaxis, but this is rare for that to happen.