LIVE-VIRUS vaccines have been well recognized as a cause of severe complications when inadvertently administered to recipients with impaired immunologic function.¹ The acquired immunodeficiency syndrome (AIDS) has been recognized as a severe immunodeficiency state caused by infection with a retrovirus, human immunodeficiency virus (HIV).² HIV infection and disease include a wide spectrum of clinical presentations, such as asymptomatic infections, chronic generalized lymphadenopathy, and frank T-cell deficiency (AIDS-related complex and AIDS).³ Although the natural history of HIV infection has only been partly defined, it is clear that patients with AIDS represent only a minority of the total number of T-cell–deficient patients . . .