Smallpox Immunization

Position on Smallpox Immunization
Board Chair-Approved June 3, 2002

The American Academy of Family Physicians endorsed the Interim Smallpox Response Plan and Guidelines when they were issued in the fall of 2001. The guidelines outline a strategy for how the nation should respond in the event of a smallpox emergency.

The CDC plan calls for the quick identification of smallpox cases and the immediate immunization and monitoring of persons around each case (ring vaccination). This approach has shown to be effective in preventing the spread of the disease in contacts and is more successful than mass immunization approaches even in urban areas with a highly mobile population.

The CDC has vaccinated a small number of public health workers—individuals who would be dispatched to investigate a possible smallpox outbreak. At this time, no additional persons have been immunized.

Since the Reponse Plan was issued, additional information is being provided by the CDC and comment is being sought by the Advisory Committee on Immunization Practices to the CDC as they review their current recommendation for the use of the vaccinia vaccine--the immunization used to protect against smallpox.

Vaccinia vaccine, while very effective against smallpox, does have risks. Persons with altered immune states (HIV infection, AIDS, leukemia lymphoma, taking immunosuppressive drugs, etc) and persons with eczema or a history of eczema can have serious or fatal complications. The vaccine is not recommended, in the absence of a smallpox outbreak, for women who are pregnant. Until their immunization site has scabbed over, those receiving the vaccine can spread the live virus in the vaccine to other persons. This can take up to six weeks. During this time they can infect persons who could suffer complications from the vaccinia virus.

Given that the federal government has not issued any warnings that smallpox is likely to be used for an attack and given that the vaccine can lead to significant and even fatal complications, the AAFP feels that the next step in preparedness should be the immunization of a limited number of persons pre-designated by the appropriate bioterrorism and public health authorities. These would be persons at the federal, state, and local levels acting as smallpox response team members who would be called upon to investigate smallpox cases and contain outbreaks.

If the federal authorities determine that the threat level has changed, then a more aggressive immunization program should be considered. In case of an outbreak, then ring containment immunization should receive the highest priority with other immunization programs initiated if found by public health authorities to be appropriate.