Effectiveness of Cervical Screening in HPV Vaccinated Women

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. Cervical samples and cervico-vaginal self-samples rinsed in first-void urine will be analysed for HPV and C. trachomatis DNA with MGP primer system followed by MALDITOF mass spectrometry on the SEQUENOM platform (HPV) and the Abbott™ PCR (Chlamydia trachomatis), respectively. With assumed \>50% participation the trial has 80% power to show non-inferiority of the infrequent vs. the frequent screening information. 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. At the study end testing the null hypotheses of no difference in the incidence of the CIN2/3 end-points between the A1 and A2 intervention arms will be done using the Mantel-Haenszel one degree of freedom chi-square statistics.