Revise guidelines for varicella immunization.
D002487:Centers for Disease Control and Prevention, U.S.; D002644:Chickenpox / Q000517:prevention & control*; D002648:Child; D006291:Health Policy; D006801:Humans; D007116:Immunization, Passive; D007231:Infant, Newborn; D012306:Risk; D014481:United States