Humoral and cellular immune responses were examined in 115 children with varicella and in 21 children who had been immunized with live varicella vaccine. Antibody determined with antibody-dependent cell-mediated cytotoxicity (ADCC) was detected earlier than neutralizing antibody (NT) in both groups. While humoral and cellular immunity were detected simultaneously in the natural varicella group, cellular immunity was detected earlier than humoral immunity in the immunized group. This suggests that ADCC, rather than NT, is involved in the early stages of recovery from varicella-zoster virus (VZV) infection.