These people include Immunocompromised people without evidence of immunity Pregnant women without evidence of immunity Neonates whose mothers developed varicella within 5 days before to 2 days after delivery Hospitalized premature infants who were born at ≥ 28 weeks gestation and whose mothers do not have evidence of immunity to varicella Hospitalized premature infants who were born at < 28 weeks gestation or who weigh ≤ 1000 g at birth, regardless of their mother's evidence of immunity to varicella Contraindications and Precautions of Varicella Vaccine Contraindications for varicella vaccine include A severe allergic reaction (eg, anaphylaxis) after a previous dose of the vaccine or to a vaccine component Known severe primary or acquired immunodeficiency (eg, due to leukemia, lymphomas, solid tumors, tumors that affect bone marrow or the lymphatic system, AIDS, severe HIV infection, treatment with chemotherapy, or long-term use of immunosuppressants) Unless people are known to be immunocompetent, family history of first-degree relatives who have congenital hereditary immunodeficiency Confirmed or suspected pregnancy The single-antigen varicella vaccine may be given to children aged 1 to 8 years who have HIV infection if their CD4 percentage is ≥ 15; it may be given to those > 8 years if their CD4 percentage is ≥ 15 and CD4 count is ≥ 200 / mcL with no evidence of immunity.