Use of an Inactivated Varicella Vaccine in Recipients of Hematopoietic-Cell Transplants

The efficacy of a heat-inactivated varicella vaccine in recipients of hematopoietic-cell transplants was evaluated in a randomized trial in which vaccination was compared with no vaccination. Patients who received the vaccine had a significantly lower incidence of zoster than patients in the control group and recovered clinically significant T-cell immunity against varicella–zoster virus earlier than did the patients who received no vaccine. Patients who received the vaccine had a lower incidence of zoster. Varicella–zoster virus causes chickenpox and becomes latent in sensory ganglia, with an estimated 250 genome equivalents per 100,000 ganglial cells. 1 – 7 When latency is disrupted, the virus is transported along neuronal axons to the skin, resulting in zoster. Since immune surveillance is critical for maintaining latency, zoster is common among immunocompromised patients, including recipients of hematopoietic-cell transplants. 8 – 16 The increased risk of zoster in these patients is associated with diminished T-cell immunity against varicella–zoster virus 14 , 16 , 17 but not with low titers of IgG antibodies to varicella–zoster virus. 18 T-cell immunity against varicella–zoster virus recovers slowly after hematopoietic-cell transplantation and often . . .