Disseminated varicella infection due to the vaccine strain of varicella-zoster virus, in a patient with a novel deficiency in natural killer T cells.

An 11-year-old girl presented with a papulovesicular rash and severe respiratory distress 5 weeks after receiving varicella vaccine. Restriction fragment length-polymorphism analysis of virus isolated from an endotracheal-tube aspirate and from bronchoalveolar lavage revealed that this patient's illness was due to the Oka vaccine strain of varicella. An extensive immunologic analysis failed to identify a known diagnostic entity to explain her susceptibility to this attenuated vaccine strain. Analysis of her lymphocytes on separate occasions, months after recovery from her illness, revealed a profound deficiency of natural killer T (NKT) cells and of NKT-cell activity, suggesting that NKT cells contribute to host defense against varicella virus.