Abstract Cervical cancer (CC) is the fourth most common female malignancy worldwide. Puerto Rico (PR) has the highest age-adjusted incidence of cervical cancer in the U.S. High-risk strains of human papillomavirus (hr-HPV) have been identified as common causative agents of CC. We aimed to characterize the prevalence of High-Risk HPV (HR-HPV) genotypes among a clinic-based sample of 368 HIV-negative women using a high-resolution approach. We used baseline data from IRB protocol 10510114. Cervical swabs underwent genomic DNA extractions followed by typification of HPV genotypes using a short-polymerase chain reaction-fragment assay (SPF10-LiPA) which detects 14 mucosal HR-HPV types (LiPA-25); 10 types (8 HR and 2LR) included in the 9-valent vaccine and 13 others not included on it. This process uses SPF10 primers to amplify a 65 bp fragment of the L1 open reading frame of HPV, followed by a reverse-hybridizationfor specific HPV genotypes by comparing the results to standardized kit controls. Cervical cytology was acquired for all participants. Data was collected from 186 women negative to intraepithelial lesions (NILM), 65 with low-grade lesions (LGSIL), 23 atypical squamous cells of undetermined significance (ASCUS) and 94 with high-grade lesions (HGSIL).Among study results, the prevalence of any HR-HPV infection was high overall (~71.5%) and higher in women who had either LGSIL or HGSIL. The top leading HR types detected were 51 (20.4%), 16 (18.5%), 52 (13.60%), 33 (13.00%) and 56 (11.00%, with other types including HPVs 35,39, 68 or 59.Nearly 34.00% of the identified cervical HR-HPV types, are not included in the 9-valent vaccine. The most common HPV types in HGSIL, included HR HPV types 16 (30.9%), 52 (18.10%), 51 (14.9%) and 33 (10.60%). In this group, only 35.20% were HPV16/18. The other 64.80% were other HR-HPV types and, based on the ASCCP guidelines, would not require a colposcopy, and could be observed in one year. Among these HGSIL (n=94) 48.9% of the HPV types were not included in the vaccine. HPV 51 was the most dominant in ASCUS (26.10%), LGSIL (20%), and women who were negative for intraepithelial lesions (NILM 22.6%). Additionally, the most prevalent HPV-HR serotypes across all cytology categories in the vaccinated cohort were 52 (11.14%), 16 (8.02%) and 31 (7.56%), whereas in the non-vaccinated cohort were HPV 16 (20.6%), 51 (17.55%), 33 (13.33%), 52 (12.29%), and 56 (11.94%).In conclusion, the high burden of other high-risk types not covered by the vaccine in women with high-grade lesions suggests that delaying immediate colposcopy might limit the identification of cervical lesions. Even though this is not a population-based study, the high prevalence of these other HR-HPV types calls for their inclusion in future generations of the vaccine. Study sponsored by 2U54MD007600-36 (8538) Research Centers in Minority Institutions of the University of Puerto Rico (NIH/NIMHD). Citation Format: Romaguera Josefina, Bianka Morales, Andrea Cortes, Ana Rosario, Andrea Padilla-Bou, Maria Frontera, Claudia Rosado, Daniela Cargas-Robles, Ana P. Ortiz, Filipa Godoy-Vitorino. Prevalence of cervical high risk HPV serotypes not covered by the 9vt vaccine in a clinic-based sample of Hispanic women living in Puerto Rico [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2141.