Clinical efficacy of intramuscular vaccinia immune globulin: a literature review.

BACKGROUND Numerous literature reports describe clinical efficacy of intramuscular vaccinia immune globulin (VIG) for complications of smallpox vaccination, prophylaxis of individuals with contraindications to vaccination, and prevention of smallpox among close contacts of patients with smallpox. METHODS We reviewed the literature regarding VIG treatment and prophylaxis of smallpox vaccine complications and the use of VIG as a preventative measure for close contacts of patients with smallpox. RESULTS Data regarding intramuscular administration of VIG for treatment of smallpox vaccine complications occurred in 16 articles, none of which reported formal controlled trials. The indications for treatment include generalized vaccinia, progressive vaccinia, eczema vaccinatum, and certain accidental implantations. Six publications suggest VIG efficacy for prophylaxis of vaccinial superinfection of eczema, burns, chickenpox, immunosuppression, pregnancy, or certain skin conditions. Prophylactic VIG has also been used in healthy military recruits to reduce the incidence of postvaccinial encephalitis. The use of intramuscular administration of VIG to prevent smallpox in contacts of patients with documented cases of smallpox is reported in 4 studies that compare contacts who received intramuscular administration of VIG with those who did not and in 1 observational study, with varying but promising results. CONCLUSIONS Although controlled clinical trials do not exist to support the use of VIG for treatment of vaccinia-related complications or prophylaxis among individuals with contraindications to smallpox vaccination, available data suggest that VIG reduces morbidity and mortality associated with progressive vaccinia (vaccinia necrosum) and eczema vaccinatum. Furthermore, VIG seems to prevent vaccinial superinfection in patients with inflammatory skin diseases or burns, given the low incidence of vaccina-related complications associated with these conditions.