Smallpox Vaccine Side Effects
For every million people vaccinated in the past, up to 52 people had a life-threatening reaction to smallpox vaccine and up to 2 people died. The numbers provided for severe or life-threatening problems are from studies done in the 1960s, when the smallpox vaccine was still routinely used in the United States. The numbers reflect how often the problems occurred in infants, children, and adults.
Severe or life-threatening smallpox side effects can include:
- Severe rash on people with eczema (atopic dermatitis), which can lead to scarring or death (about 1 out of 26,000 people vaccinated)
- Encephalitis, which can lead to permanent brain damage or death (about 1 out of 83,000 people vaccinated)
- Skin and tissue destruction starting at the vaccination site and spreading to the rest of the body, which can lead to scarring or death (about 1 out of 667,000 people vaccinated)
- Vaccinia virus infection in an unborn child that can lead to premature delivery, skin rash with scarring, stillbirth, or death of the child after delivery (rare; fewer than 50 cases have been reported throughout the world in the last 100 years).
Symptoms that may indicate something serious include but are not limited to:
- Trouble breathing, hoarseness, or wheezing
- Hives, pale skin, weakness, a fast heartbeat, or dizziness
- A vaccination site that is not healing
- A rash or sore on other parts of your body
- An eye infection
- A lasting headache or fever
- Confusion, seizures, or trouble staying awake
- Chest pain, shortness of breath, rapid or unusual heartbeat, or unusual fatigue
- Any unexpected health problem.
If any of these serious problems do occur, call a doctor or get the person to a doctor right away. Tell the doctor what happened, the date and time it happened, and when the smallpox vaccine was given.