What if a told you that there is a cancer that is largely preventable? A cancer that affects mostly women in the prime of their lives. We are talking about cervical cancer, which is primarily caused by sexually transmitted Human Papillomavirus (HPV). In 2022, there were approximately 660,000 new cases of cervical cancer and 350,000 deaths worldwide. Alarmingly, approximately 90% of these deaths occurred in low-and middle-income countries. Despite the efficacy of the HPV vaccine to prevent HPV infection and HPV-related cancers, many children in low-and middle-income countries do not have access to it. One major barrier has been the cost and logistical challenges of delivering the standard multi-dose vaccinations. Initially, the World Health Organization (WHO) Strategic Advisory Group of Experts on Immunization (SAGE) recommended a three-dose schedule (initial dose followed by booster shots 6 and 12 months later). A recent clinical trial showed that one dose provides comparable efficacy and long-lasting protection as for the two and three-dose regimen. Based on this data and data from observational studies, SAGE updated its recommendation to a single-dose schedule in 2022.
This shift is a breakthrough, particularly for low-income settings, as it simplifies implementation, reduces costs, and eliminates the burden of follow-up vaccinations. However, key data is missing to demonstrate that one dose is as effective in immunocompromised children, such as children living with HIV, compared to children without HIV. People living with HIV are at higher risk of acquiring HPV and developing HPV-related cancers. In fact, cervical cancer and other HPV-related cancers disproportionately affect individuals with HIV, particularly in low- and middle-income countries and underserved communities in high-income nations.
The U.S National Cancer Institute (NCI)’s US-Latin American-Caribbean HIV/HPV-Cancer Prevention Clinical Trials Network (ULACNet) is conducting collaborative research to address these challenges. This initiative develops evidence-based strategies to improve the prevention, detection and treatment of HPV-related cancers in people living with human immunodeficiency virus (HIV) infection. At Fred Hutch, Drs. Ann Duerr, Denise Galloway and Margaret Madeleine, and their teams, with collaborators in Peru, Brazil, Haiti, and at the US NCI are contributing to these efforts, including through a ULACNet-backed clinical trial called ‘OPTIMO’.
In a recent publication, Dr. Duerr and her team described the OPTIMO trial’s design, stating that they “compare immune responses to HPV vaccination in CLWH [children living with HIV] by measuring antibody and memory B cell (Bmem) responses after 1, 2 or 3 doses of the 9-valent HPV (9vHPV) vaccine, Gardasil 9. A comparison group of children without HIV receives 1 dose of the vaccine. The durability of the response will be assessed at 24 months after the last dose of a given regimen by administrating a vaccine booster dose to elicit anamnestic responses.” The study is fully enrolled in in Peru, Brazil and Haiti. All samples from Peru have now been collected and are currently being analyzed. Study visits continue in Brazil and Haiti and collection will go until July 2026.
The OPTIMO trial has enrolled 3 groups of children living with HIV who received 3, 2, or 1 dose. Responses in these groups will be comparted to those in a group of children without HIV who received one dose, which is expected to confer protection in uninfected children. Throughout the clinical trial, children living with HIV continue receiving their routine HIV care, including antiretroviral therapy (ART). Dr. Duerr presented preliminary data at a recent international scientific conference (IPVC 2024): HPV16 and HPV18 binding antibody responses were available from all 3 study sites 1 month after a single vaccine dose (peak responses). The one-month responses were lower in children living with HIV than in HIV-negative children, although stronger responses were seen in children with HIV after 2 or 3 doses. Initial data from a durability timepoint (at 18 months) after a single dose were available from Peru only; these responses were similar in children with or without HIV. Dr. Delia Pinto-Santini, lead author of the article, emphasized that it is too early for definitive conclusions from these results and that data from Brazil and Haiti will be available in 2026. Stay tuned!
Pinto-Santini D, Jalil EM, Fernandes GT, Hilaire G, Kolevic L, Cabello R, Grinsztejn B, Pape W, Deschamps MM, House MG, Brofsky E, Sahasrabuddhe VV, Dasgupta S, Pasalar S, Madeleine MM, Carter J, Prabhu PR, Galloway D, Duerr A. 2025. ULACNet-301, OPTIMO protocol: optimizing HPV vaccination regimen for cancer prevention in children and adolescents living with HIV. BMC Cancer. 25(1):151.
Joss Landazuri is a PhD candidate at the University of Washington in the Microbiology program working at the intersection of biomedical science, public policy, and science diplomacy. As a Latina scientist, communicator, and policy advocate, she is passionate about leveraging her academic training, personal background, and cultural heritage to engage underserved communities in both science and the policymaking process.
For the Media