The human papilloma virus (HPV) vaccine, Cervarix, not only has the potential to prevent cervical cancer but also other HPV-caused common cancer types, shows a multinational clinical trial, involving nearly 20,000 young women. That effectiveness endured for the study’s entire follow-up, of up to four years, the researchers noted.
“The study confirms that targeting young adolescent girls before sexual debut for prophylactic HPV vaccination has a substantial impact on the incidence of high grade cervical abnormalities,” said corresponding author Dan Apter, director, The Sexual Health Clinic, Family Federation of Finland, Helsinki.
The vaccine was extremely effective in young women who had never been infected with HPV. It protected nearly all from HPV-16 and 18, and protected 50-100 percent against different grades of precancerous transformation of cervical cells caused by other strains of HPV. The women were followed for up to four years post-vaccination. The vaccine was distinctly more effective among those aged 15-17 than those aged 18-25, underscoring the value of vaccinating young adolescents, Apter added.
The lower efficacy in the oldest age group may result from a larger proportion of women in that age group having had persistent infections at the time of vaccination, he said. The study is the final report from the Papilloma Trial Against Cancer in Young Adults (PATRICIA), a multinational clinical trial, encompassing 14 countries in Europe, the Asia-Pacific region, North America, and Latin America, and it confirms previous reports in this trial.