Virus Home > Smallpox Vaccine Side Effects
A few common side effects of the smallpox vaccine include a high fever, a mild rash that improves without medication, and blisters on other parts of the body. The severity of the side effects is generally mild to moderate. However, there is also a small risk of developing life-threatening reactions to the smallpox vaccine, such as encephalitis.
Does the Smallpox Vaccine Cause Side Effects?A vaccine, like any medicine, can cause serious problems. There is a very small risk of the smallpox vaccine causing serious harm or death.
The following information is about known reactions to smallpox vaccine. There may be other unknown side effects.
(This article covers many, but not all, of the possible side effects with the smallpox vaccine. Your healthcare provider can discuss a more complete list with you.)
Mild-to-moderate smallpox vaccine side effects can include:
- Feeling sick enough to miss work (about 1 out of 10 to 20 people vaccinated)
- Fever of over 100°F (about 1 out of 10 people vaccinated)
- Mild rash that gets better without medicine (about 1 out of 12 people vaccinated)
- Blisters on other parts of the body (about 1 out of 10,000 people vaccinated).
Moderate-to-severe side effects of the smallpox vaccine can include:
- Eye infection from touching your eye if you have vaccine virus on your hand. This can lead to a loss of vision in the infected eye (about 1 out of 45,000 people vaccinated).
- Rash on entire body; this rash usually goes away without problems (about 1 per 15,000 people vaccinated).
- Inflamed heart, which can be a mild to life-threatening condition (about 1 out of 10,000 people vaccinated for the first time).
If any of these side effects occur after you receive the smallpox vaccine, call or visit your healthcare provider.