(A52) Post-marketing surveillance of human papillomavirus (HPV)-related high-grade cervical disease in a cohort of Chinese women who received the 9-valent HPV vaccine

Publication Number: 335

Background: Cervical cancer is the 3rd leading cause of female cancer and the 2nd leading cause of cancer death in Chinese women 15 to 44 years of age. Nearly all cases of cervical cancer are caused by HPV. The 9-valent HPV (9vHPV; Gardasil 9 [Merck & Co., Inc., Rahway, NJ, USA]) vaccine has been approved in China for women aged 16–26 years since 2018.

Objectives: However, real world evidence of the impact of 9vHPV vaccine for the prevention of high-grade cervical lesions in Chinese women is not yet available.

Methods: Women aged 16–26 who received ≥1 dose of the 9vHPV vaccine were identified from the Ningbo Regional Health Information Platform (NRHIP). The primary 9vHPV vaccinated cohort included women vaccinated per protocol (3 doses administered within 12 months; ≥ eight weeks between doses 1 and 2). A sub-cohort of 9vHPV vaccinated women who had cervical HPV negative and TCT (Thinprep Cytology Test) negative results within one year before the cohort enrollment date (vaccinated HPV test-negative sub-cohort) and a matched unvaccinated HPV test-negative cohort, were also assessed. Outcomes were the occurrence of new-onset high-grade cervical disease (cervical intraepithelial neoplasia 2/3 [CIN2/3]), adenocarcinoma in situ (AIS), and invasive cervical cancer (ICC).

Results: From 25 January 2019 to 31 March 2021, 102,791 doses of the 9vHPV vaccines were administered and 41,609 women received ≥1 9vHPV dose. The 9vHPV vaccinated cohort, vaccinated HPV test-negative sub-cohort, and unvaccinated cohort comprised 25,107, 160, and 466 women, respectively. In the 9vHPV vaccinated cohort, one case of CIN2/3 was identified in a woman with unknown HPV and cytological testing status at enrollment, therefore HPV infection prior to vaccination could not be excluded. No new-onset CIN2/3 cases were observed in the vaccinated HPV test-negative sub-cohort and one new-onset case was observed in the unvaccinated cohort. Furthermore, no new-onset cases of AIS or ICC were observed during the study period in the three cohorts.

Conclusions: These findings demonstrate that new-onset high-grade cervical disease can be monitored through surveillance of Chinese women registered in the NRHIP. However, considering the limited number of vaccinated women and the short follow-up period, it needs more time to assess the real-world effectiveness of 9vHPV vaccination in China.