TY - JOUR
T1 - Evaluating the biomedical and behavioral drivers of HIV incidence decline in adolescent girls and young women in Uganda
T2 - A mathematical modeling study
AU - Akullian, Adam
AU - Ssempijja, Victor
AU - Breidenbecker, Daniel
AU - Nalugoda, Fred
AU - Nakigozi, Gertrude
AU - Santelli, John
AU - Kreniske, Philip
AU - Chang, Larry W.
AU - Reynolds, Steven J.
AU - Ssekubugu, Robert
AU - Gray, Ronald H.
AU - Wawer, Maria J.
AU - Quinn, Thomas C.
AU - Galiwango, Ronald M.
AU - Probert, William J.M.
AU - Imai-Eaton, Jeffrey W.
AU - Ratmann, Oliver
AU - Fraser, Christophe
AU - Kagaayi, Joseph
AU - Kigozi, Godfrey
AU - Kate Grabowski, M.
AU - Serwadda, David
N1 - Publisher Copyright:
This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
PY - 2026/3
Y1 - 2026/3
N2 - HIV incidence among adolescent girls and young women (AGYW) in eastern and southern Africa has declined substantially over the past two decades. These declines are often attributed to biomedical HIV prevention strategies, though concurrent changes in sexual behavior may also contribute. We evaluated the contributions of biomedical and behavioral drivers to historical incidence decline in AGYW and projected their impact on incidence trajectories over the next 30 years. Methods and findings We conducted a mathematical modeling study using data from the Rakai Community Cohort Study (RCCS), an open, population-based cohort of adults aged 15–49 years in 30 communities in Rakai, Uganda. We used an agent-based HIV-1 transmission model calibrated to cohort data to estimate HIV incidence trends among AGYW, aged 15–24 and to quantify the independent and combined effects of antiretroviral therapy (ART), voluntary medical male circumcision (VMMC), and changes in age at first sex (AFS). HIV incidence among women aged 15–24 declined by 71% between 2000 and 2019, from 1.57 to 0.45 per 100 person-years, representing the largest decline across female age groups in the cohort. Increasing AFS over the study period (by approximately 3 years in women and 2 years in men) was the largest contributor to incidence declines among adolescent women aged 15–19, averting 17% of cumulative infections between 2000 and 2020 and 37% between 2000 and 2050. Among women aged 20–24, ART scale-up had the greatest impact, averting 13% of infections by 2020 and 43% by 2050. VMMC contributed modestly to historical declines but had larger projected effects over longer time horizons. ART, VMMC, and delays in AFS acted additively to reduce HIV incidence among AGYW. Study limitations include reliance on self-reported sexual behavior and the use of a mathematical model that cannot capture all real-world sexual network dynamics. Conclusions Both biomedical HIV interventions and broader behavioral changes contributed to declines in HIV incidence among AGYW. Sustaining continued incidence declines in young women will require maintaining both the protective changes in sexual behaviors and effective biomedical interventions.
AB - HIV incidence among adolescent girls and young women (AGYW) in eastern and southern Africa has declined substantially over the past two decades. These declines are often attributed to biomedical HIV prevention strategies, though concurrent changes in sexual behavior may also contribute. We evaluated the contributions of biomedical and behavioral drivers to historical incidence decline in AGYW and projected their impact on incidence trajectories over the next 30 years. Methods and findings We conducted a mathematical modeling study using data from the Rakai Community Cohort Study (RCCS), an open, population-based cohort of adults aged 15–49 years in 30 communities in Rakai, Uganda. We used an agent-based HIV-1 transmission model calibrated to cohort data to estimate HIV incidence trends among AGYW, aged 15–24 and to quantify the independent and combined effects of antiretroviral therapy (ART), voluntary medical male circumcision (VMMC), and changes in age at first sex (AFS). HIV incidence among women aged 15–24 declined by 71% between 2000 and 2019, from 1.57 to 0.45 per 100 person-years, representing the largest decline across female age groups in the cohort. Increasing AFS over the study period (by approximately 3 years in women and 2 years in men) was the largest contributor to incidence declines among adolescent women aged 15–19, averting 17% of cumulative infections between 2000 and 2020 and 37% between 2000 and 2050. Among women aged 20–24, ART scale-up had the greatest impact, averting 13% of infections by 2020 and 43% by 2050. VMMC contributed modestly to historical declines but had larger projected effects over longer time horizons. ART, VMMC, and delays in AFS acted additively to reduce HIV incidence among AGYW. Study limitations include reliance on self-reported sexual behavior and the use of a mathematical model that cannot capture all real-world sexual network dynamics. Conclusions Both biomedical HIV interventions and broader behavioral changes contributed to declines in HIV incidence among AGYW. Sustaining continued incidence declines in young women will require maintaining both the protective changes in sexual behaviors and effective biomedical interventions.
UR - https://www.scopus.com/pages/publications/105034027000
UR - https://www.scopus.com/pages/publications/105034027000#tab=citedBy
U2 - 10.1371/journal.pmed.1004993
DO - 10.1371/journal.pmed.1004993
M3 - Article
C2 - 41880347
AN - SCOPUS:105034027000
SN - 1549-1277
VL - 23
JO - PLOS Medicine
JF - PLOS Medicine
IS - 3 March
M1 - e1004993
ER -