Questions about Adverse Side Effects and Who Should Not be Immunized with ACAM2000
The vaccine may cause myocarditis and pericarditis, which are inflammation and swelling of the heart and surrounding tissues and can be very serious. Based on clinical studies, myocarditis and/or pericarditis occur in 1 in 175 adults who get the vaccine for the first time.
Serious health problems, including those that are life-threatening, can also occur in unvaccinated people who are accidentally infected by someone who has recently received the vaccine. In particular, unvaccinated people who are pregnant, or have problems with their heart or immune system, or have skin problems like eczema, dermatitis, psoriasis, and have close contact with a vaccine recipient are at an increased risk for serious problems if they become infected with the vaccine virus, either by being vaccinated, or by being in close contact with a person who was vaccinated.
more:
https://www.fda.gov/vaccines-blood-biologics/vaccines/acam2000-smallpox-vaccine-questions-and-answers