The immunogenicity of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine (Cervarix®, GlaxoSmithKline Biologicals) administered according to its licensed vaccination schedule (3-dose, 3D) and formulation (20 μg of each HPV antigen; 20/20F) has previously been demonstrated. This partially-blind, controlled, randomized trial (NCT00541970) evaluated 2-dose (2D) schedules using the licensed 20/20F or an alternative formulation containing 40 μg of each antigen (40/40F), compared with the licensed 3D schedule. Healthy females stratified by age (9-14, 15-19, 20-25 y) were randomized to receive 2 doses of 20/20F at Months (M) 0,6 (n=240), 40/40F at M0,6 (n=241) or 40/40F at M0,2 (n=240), or 3 doses of 20/20F at M0,1,6 (licensed schedule/formulation, n=239). One month after the last dose, the 3D schedule was not immunologically superior to 2D schedules except in the 40/40F M0,2 group for HPV-16 (lower limit of 95% CI geometric mean antibody titer (GMT) ratio [2D/3D] < 0.5). For both HPV-16 and HPV-18, the 2D schedules in girls 9-14 y were immunologically non-inferior to the 3D schedule in women 15-25 y (the age group in which efficacy has been demonstrated) (upper limit of 95% CI for GMT ratio [3D/2D] < 2) one month after the last dose. At Month 24, non-inferiority was maintained for the 2D M0,6 schedules in girls 9-14 y versus the 3D schedule in women 15-25 y. All formulations had acceptable reactogenicity and safety profiles. These results indicate that the HPV-16/18 vaccine on a 2D M0,6 schedule is immunogenic and generally well tolerated in girls 9-14 y and that the 2D schedule is likely adequate for younger females.

In developing countries, risk of human papillomavirus (HPV) infection may be increased by the high prevalence of human immunodeficiency virus (HIV) infection. We evaluated the safety and immunogenicity of the HPV-16/18 AS04-adjuvanted vaccine in HIV-infected women in South Africa. Asymptomatic HIV-positive women aged 18-25 years (N=120) were stratified by CD4⁺ T-cell count and randomised (1:1) to receive HPV-16/18 vaccine (Cervarix®; GlaxoSmithKline Vaccines) or placebo (Al[OH]3) at 0, 1 and 6 months (double-blind). HIV-negative women (N=30) received HPV-16/18 vaccine (open label). Anti-HPV-16/18 antibody and CD4⁺ T-cell responses, CD4⁺ T-cell count, HIV viral load, HIV clinical stage and safety were evaluated for 12 months. The safety and reactogenicity profile of the HPV-16/18 vaccine was comparable in HIV-positive and HIV-negative women. Irrespective of baseline HPV status, all HIV-positive and HIV-negative women who received the HPV-16/18 vaccine were seropositive for both HPV-16 and HPV-18 after the second vaccine dose (month 2) and remained seropositive for both antigens at month 12. Anti-HPV-16/18 antibody titres at month 12 remained substantially above levels associated with natural infection. The HPV-16/18 vaccine induced sustained anti-HPV-16/18 CD4⁺ T-cell responses in both HIV-positive and HIV-negative women. No impact of baseline CD4⁺ T-cell count or HIV viral load was observed on the magnitude of the immune response in HIV-positive women. In HIV-positive women, CD4⁺ T-cell count, HIV viral load and HIV clinical stage were unaffected by HPV-16/18 vaccine administration. In conclusion, the HPV-16/18 AS04-adjuvanted vaccine appears immunogenic and well-tolerated in women with HIV infection. Study ID: 107863/NCT00586339.

PATH, GlaxoSmithKline Biologicals SA. ClinicalTrials.gov identifier NCT01262872.