Safety and immunogenicity of the HPV-16/18 AS04-adjuvanted vaccine: a randomized, controlled trial in adolescent girls

Abstract

Purpose: Immunization of girls against oncogenic human papillomavirus (HPV) types before sexual debut is important for cervical cancer prevention. This phase III blinded, randomized, controlled trial in adolescent girls assessed safety of the HPV-16/18 AS04-adjuvanted vaccine.

Methods: Girls (mean age 12 years) in 12 countries received the HPV-16/18 L1 virus-like particle AS04-adjuvanted vaccine (N = 1,035) or hepatitis A virus vaccine as control (N = 1,032) at 0, 1, and 6 months. The primary objective was to compare the occurrence of serious adverse events (SAEs) between groups. HPV-16 and HPV-18 antibody titers were assessed by enzyme-linked immunosorbent assay post-vaccination.

Results: Up to study month 7, 11 girls in the HPV-16/18 vaccine group reported 14 SAEs and 13 girls in the control group reported 15 SAEs. The difference in SAE incidence between groups was .20% (95% CI, -.78, 1.20). No SAE in the HPV-16/18 vaccine group was considered related to vaccination or led to withdrawal. The incidence of solicited local and general symptoms up to 7 days post-vaccination was moderately higher with the HPV-16/18 vaccine than with control. The incidence of unsolicited symptoms, new onset of chronic diseases, and medically significant conditions was similar between groups. All girls seroconverted for both antigens after three doses of the HPV-16/18 vaccine; geometric mean titers were 19,882.0 and 8,262.0 EU/mL for anti-HPV-16 and -18 antibodies, respectively, in initially seronegative girls.

Conclusions: The HPV-16/18 AS04-adjuvanted vaccine was generally well tolerated and immunogenic when administered to young adolescent females, the primary target of organized vaccination programs.

Trial registration: ClinicalTrials.gov NCT00196924.