Is the vaccination against smallpox effective?
A. Yes. The vaccination against smallpox is extremely effective in preventing the disease. We know this because by the 1970s, thanks to the vaccine, the disease was eradicated from the U. S., and later declared eradicated worldwide in 1980. In fact, if you are exposed to anyone with smallpox and are vaccinated within 4 days of your exposure, there is a 90 percent chance that you will be protected from developing smallpox disease.
