Altogether 16.500 1992-1995 born women vaccinated with the bi-valent human papillomavirus type 16 and 18 (HPV16/18) vaccine as adolescents either at the age of 12 to 15 or at the age of 18 will be invited to an effectiveness trial at the age of 22 years, and randomized into Arms A1 and A2, and A3, respectively.