Postexposure prophylaxis smallpox

Other potential uses of cidofovir that are currently under investigation include treatment of the polyomavirus-associated progressive multifocal leukoencephalopathy syndrome in patients with AIDS, postexposure prophylaxis against smallpox, and topical treatment of molluscum contagiosum. Topical cidofovir is not currently available in a standardized preparation. 

Smallpox vaccine is not recommended for use in certain groups who may be at risk for complications of the vaccine, in up to 0.2% or more of immunized populations, immunosuppressed individuals, pregnant women, and patients with atopic dermatitis may develop complications related to vaccinia, the orthopox virus used in smallpox vaccine. Vaccinia immunoglobulin can be given to those at risk for these complications. Smallpox vaccine can also be given up to 4 days postexposure as postexposure prophylaxis with significant reduction in mortality. 

D. Vaccine/Prophylaxis. Smallpox vaccine (vaccinia virus) is a licensed live poxvirus vaccine that induces strong cross-protection against smallpox. Reliable data are sparse as to efficacy and durability of protection. The duration vaccinia induced immunity is at least 3 years. Vaccine immunity may prevent or modify illness. Fully immune individuals exposed to the virus by the respiratory route may develop fever, sore throat, and conjunctivitis ("contact fever") lasting several days. The vaccine is administered by dermal scarification or intradermal jet injection. The appearance of a vesicle or pustule within several days indicates that the vaccine will be effective. Other available countermeasures include the postexposure use of Vaccinia immune globulin or primary vaccination within 3-4 days of exposure yields some protection. 

Evidence indicates that vaccinia-immune globulin is of value in postexposure prophylaxis of smallpox when given (a) within the first week following exposure and (b) concurrently with vaccination.121 However, the prophylactic use of VIG should be carefully weighed vis-a-vis the risk of attenuating the immune response to booster vaccination. 

Vaccinia vaccine remains the preeminent countermeasure for preexposure prophylaxis against smallpox. Vaccinia vaccination, vaccinia immune globulin, and methisazone each possess some efficacy in postexposure prophylaxis. 

Vaccines. Anthrax and smallpox vaccines can be used before exposure and also for postexposuie prophylaxis. A pentavalent (ABODE) botulinum toxoid is currently used for laboratory workers at high risk of exposure. It is not effective for postexposure prophylaxis. Vaccines are not currently available for plague, tularemia, or viral hemorrhagic fevers. 

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