Is the small pox vaccination worth the risk? Out of the 21,698 volunteers for the vaccine 1 has died and 6 have become ill. The CDC has barred anyone with heart disease from recieving the vaccine. In the 60's when the vaccine was routine 1-3 deaths and 14-52 seriious complications for every million vaccinations occured. The CDC is unsure why the small pox vaccinations seem to be causing serious heart effects but they say they are determined to discover the reason. Until a cause is found the CDC reccomends that people with heart conditions not volunteer for the vaccine.