HPV vaccine efficacy at up to 6 years

To protect against cervical cancer, HPV vaccines need to have long-term efficacy. The HPV-16/18 AS04-adjuvanted vaccine has been shown to have good efficacy at up to 3 years. Now, the 6-year results have been reported.

The according-to-protocol efficacy cohort included 465 women in the vaccine group, and 454 in a placebo group. The total vaccinated cohort (TVC) included 560 and 553 women in these respective groups. After up to 6.4 years of follow-up, vaccine efficacy against incident infections with HPV16/18 was 95.3%. Vaccine efficacy against cervical epithelial neoplasia grade 2 and above (CIN2+) was 100% for lesions associated with HPV16/18, and 72% for all lesions.

Antibody concentrations remained at least 12 times as high as after natural infection with HPV. The vaccine was well-tolerated with no related adverse events.

The HPV-16/18 AS04-adjuvanted vaccine is effective and safe at up to 6.4 years.

The GlaxoSmithKline vaccine HPV-007 study group. Sustained efficacy and immunogenicity of the human papillomavirus (HPV)-16/18 AS04adjuvanted vaccine: analysis of a randomised placebo-controlled trial up to 6.4 years. Lancet 2009; 374:1975–1985; Clifford GM. Global access to HPV vaccination: what are we waiting for? Ibid:1948–1949 (comment).