title: Possible mechanisms for maintaining immunity to varicella-zoster virus. Clinical observations.
mesh_terms: D000328:Adult; D002644:Chickenpox / Q000276:immunology*; D002675:Child, Preschool; D005260:Female; D014645:Herpesvirus 3, Human / Q000276:immunology; D006801:Humans; D007112:Immunity, Maternally-Acquired; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011645:Puerperal Infection; D014427:Twins