Latest safety data also confirm the low levels of adverse events associated with the vaccines.
In a study of 1113 healthy women aged 15-25 years vaccinated with the anti-HPV 16/18 vaccine, Cervarix, sustained immunogenicity and 100% efficacy against HPV 16 and 18 related cervical intraepithelial neoplasia 2 (CIN2+) lesions was reported at 7.3 years follow up – the longest to date with the vaccine. Medically significant adverse events occurred in 8.1% of vaccinated women and 6.2% of placebo-treated women, and serious adverse events occurred in 1.8% and 2.4% respectively.
Presenting the data at a late-breaker session of the congress, trial investigator Dr Newton De Carvalha, from the Hospital de Clínicas da Universidade Federal do Paraná, Curitiba – Paraná, Brazil, concluded that that the vaccine was highly effective against HPV infection and cytohistological endpoints associated with HPV 16/18, and had similar safety to placebo.
In a second analysis, Dr Elmar Joura, from the Medical University of Vienna, Austria, showed efficacy data on 1350 women who took part in placebo controlled trials of the anti-HPV 6,11,16,18 vaccine, Gardasil, following treatment for cervical, vulvar or vaginal precancers or genital warts. These data, collected an average 1.5-1.6 years post therapy, showed efficacy of up to 74% in preventing HPV 6/11/16/18 associated CIN, and efficacy of up to 79% for prevention of further precancerous vulvar or vaginal lesions or genital warts.
Dr Joura concluded that women who have been treated for cervical, vulvar or vaginal pre-cancer or genital warts, and are therefore at increased risk of further disease, can be told that they too will benefit from HPV vaccination.