Cervical intraepithelial neoplasia in women who had vaccination against HPV

Objective To investigate the characteristics of women developing cervical intraepithelial neoplasia who had had a vaccination against human papillomavirus ( HPV ). Methods A retrospective cohort study was carried out of women diagnosed with moderate or severe cervical dysplasia ( CIN 2+) in four Italian centers between 2015 and 2017. All women included had had previous bivalent or quadrivalent vaccination against HPV . Results The present study included 43 patients affected by CIN 2+. The median age was 28 (range, 21–41) years. Ten (23.3%) patients did not have a diagnosis of specific HPV type(s) involved: high‐risk HPV was detected in 7 (16.3%) women while HPV testing was negative in 3 (6.9%) women. Lesions related to HPV 16 were found in two patients. HPV types covered by nonavalent vaccination were diagnosed in 27/33 (81.8%) women. HPV types not covered by nonavalent vaccination were diagnosed in 6 (18.2%) women. Co‐infections are most commonly detected in women with HPV s other than those included in the nonavalent vaccination ( P =0.024). Conclusion Cervical dysplasia occurring after HPV vaccination is a rare condition. Theoretically, nonavalent vaccination should improve protection against more than 80% of HPV ‐related lesions compared to other vaccines.