Human papilloma virus (HPV) causes cervical cancer. HPV vaccination is highly effective in primary prevention. There is less known about a possible effect of secondary prevention in women already infected with HPV. Our study proposes to investigate this efficacy in women with precursors of cervical cancer. We hypothesize that HPV vaccination after LEEP for CIN reduces recurrence. This study is highly prioritized by the Dutch society of obstetrics and gynaecology.