Fever, malaise and regional lymphadenopathy are common following vaccination. However, fever is less common in adults than in children after vaccination or revaccination. Also, a considerable injection site reaction is expected with successful vaccination. Accidental spread of the vaccine virus from the vaccination site to other parts of the body is one of the most frequent complications of vaccination. It usually results when the vaccinated individual touches the infected vaccination site and unintentionally transfers the virus to other parts of their body. Generalized vaccinia (manifested by skin lesion(s) at locations other than the vaccination site) among persons without underlying illnesses is characterized by a vesicular rash (a rash consisting of blisters) of varying size. The rash generally goes away and requires little or no therapy except among patients who have serious underlying illnesses. The serious side effects of smallpox vaccination have been well documented, for example, in this publication: Lane JM, Ruben FL, Neff JM, Millar JD. Complication of smallpox vaccination, 1968. N Engl J Med 1969;281:1201-8. More severe complications that may follow either primary vaccination or revaccination include nervous system involvement by the vaccine such as postvaccinial encephalitis, encephalomyelitis, and encephalopathy, and more serious skin infections including progressive vaccinia (vaccinia necrosum), which usually occurs in individuals with weakened immune systems, and eczema vaccinatum, which usually occurs in people with eczema and related skin diseases (see CDC website for photos of these complications). Such complications may result in severe disability, permanent neurological damage, and/or death. Although a rare event, approximately 1 death per million primary vaccinations and 1 death per 4 million revaccinations have occurred after smallpox vaccination. Death is most often the result of postvaccinial encephalitis or progressive vaccinia. Death has also been reported in unvaccinated individuals to whom the virus was spread by contact with vaccinated individuals. Please see the package insert for how to minimize the risk of spreading the virus to another area of the body or to another person. | 
