Candidates for postexposure prophylaxis include People with leukemia, immunodeficiencies, or other severe debilitating illness Susceptible pregnant women Neonates whose mother developed chickenpox within 5 days before or 2 days after delivery Neonates born at < 28 weeks and exposed to a nonmaternal source even if their mother has evidence of immunity (exposed neonates born at ≥ 28 weeks should receive immune globulin if their mother has no evidence of immunity) The VariZIG immune globulin should be given as soon as possible (and within 10 days of exposure) and may modify or prevent varicella.