There is no. Smallpox in nature now. The vaccine has potential side effects. The American public has not received routine smallpox vaccinations since 1972. All natural sources of smallpox have been eradicated. According to the CDC “The U.S. government has enough vaccine to vaccinate every person in the United States in the event of a smallpox emergency.” This is part of Emergency Prepared & Response for >
Like the oral polio . The risk of taking it, although small, is higher than the risk of acquiring smallpox.
Proof vaccines work! Because small pox is gone from the planet essentially and there is no more real risk to the general public. Thus a vaccine has essentially obliterated a disease that killed thousands before 1972. Strong proof on the value of vaccines.