Assoc. Prof.
Nguyen Van Anh
Deputy Director of Center for Biomedical Researches, National Institute of Hygiene and Epidemiology, Hanoi
Title: Immunogenicity of HPV Vaccine in Female Sex Workers in Vietnam
Nguyen Van Trang1, Le Anh Tuan1, Chu Thi Ngoc Mai, Le Thi Khanh Ly1, Tran Hoang My Lien1, Nguyen Thanh Chung1, Dao Thi Thanh Huyen1, Nguyen Thi To Uyen2, Nham Thi Tuyen Thanh3, Tran Thi Hong Nhung3, Chau Quang4,5, Claire Von Mollendorf4,5, Gerald Murray4,6,7, Suzanne M. Garland4,6,7, Kathryn Bright4, Paul V Licciardi4,5, *Kim Mulholland4,5,8 and *Zheng Quan Toh4,5*
1National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam
2Do Son Health Center, Hai Phong, Vietnam
3The Center for Supporting Community Development Initiatives, Hanoi
4Murdoch Children’s Research Institute, Parkville, Victoria, Australia
5Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
6Regional WHO HPV Reference Laboratory, The Royal Women’s Hospital, Parkville, Victoria, Australia
7Department of Obstetrics, Gynaecology and Newborn Health, The University of Melbourne, Parkville, Victoria, Australia
8London School of Tropical Medicine, UK
Abstract
Female sex workers (FSW) are at high risk of HPV infection, the prerequisite for cervical cancer. They could be a target group for HPV vaccination, but their expected immune response to the HPV vaccine is unclear due to potential previous exposure to the virus. We conducted a pilot study (NCT04590521) in Hai Phong, Vietnam, between September 2022 and April 2023 to evaluate HPV vaccine immunogenicity among FSW aged 18–26 years. All participants received the standard three-dose schedule (0, 2 and 6 months) of the quadrivalent Gardasil® vaccine (4vHPV). Cervical swabs were collected at baseline and at 2 and 6 months post-first dose to detect high-risk HPV DNA and cervical abnormalities. Blood samples were collected at baseline and at 2, 3, 6 and 7 months to determine neutralising antibody (NAb) and IgG antibody responses to HPV16, 18, 52 and 58 using pseudovirus-based-NAb and VLP-based ELISA assays, respectively. A total of 63 FSW with a median age of 23.4 years (IQR 21.6-25.4) were recruited. The prevalence of any high-risk HPV type and HPV16/18 infection at baseline was 28.6% (18/63) and 9.5% (6/63), respectively. Three (4.7%) and four (6.3%) participants were seropositive for HPV16 and HPV18 at baseline, respectively. After the first and second doses, 90.0% of participants were seropositive for HPV16, while 55.0% (33/60) and 91.4% (53/58) were seropositive for HPV18, respectively. By Month 7, all participants were seropositive to both HPV16 and HPV18. Higher NAb responses were observed among HPV-DNA negative participants at baseline compared with HPV-DNA positive participants [HPV16: GMR: 1.63 (95%CI: 1.47- 1.81, p= 0.04); HPV18: 1.49 (95%CI: 1.27-1.74, p=0.06)]. Seropositivity to HPV52 and HPV58 over the six-month period ranged from 8.3%-15.7% and 5.2%-9.8%, respectively. Thus at least 2 doses of 4vHPV elicited robust antibody to HPV16 and HPV18 among FSW. Further studies are needed to evaluate the effectiveness of HPV vaccination in this high-risk group.
(The study’s results have been presented in part at Journal of Infectious Diseases, 2026, DOI: 10.1093/infdis/jiag112)
Biography of the presenting author
Dr. Nguyen Van Trang is currently a Deputy Director and Associate Professor at the Center for Biomedical Researches, NIHE, Vietnam. She also serves as a member of the Vietnam National Ethical Committee since 2008. Dr Trang obtained PhD degree at the Ohio State University in 2005. Her research interests include molecular epidemiology, virology, immunology, diagnostics, and vaccinology for rotaviruses, other gastroenteritis pathogens, and human papillomaviruses. In particular, she focuses on the development of diagnostics and vaccines as well as immune responses and effectiveness assessment after vaccination for these pathogens. Dr Trang has published close to 90 articles in domestic and international journals and a number of textbooks.
Presenting author details
Full name: Nguyen Van Trang
Contact number: (84)986688899
Email: nvt@nihe.org.vn
LinkedIn: Trang Nguyen
Researchgate: https://www.researchgate.net/profile/Trang-Nguyen-909?ev=hdr_xprf
Google Scholar: https://scholar.google.com/citations?user=w6hI5n0AAAAJ&hl=en
ORCID: 0000-0002-0993-424