A one-way (participant) blinded interim analysis among the 1992-born study participants in A1 and A3 arms, who have attended the 2nd study visit at the age of 25 years, will be performed in 2017 for assuring no statistically significant differences in the cervical intraepithelial neoplasia grade 2/3 (CIN2/CIN3) incidences of the two arms.