CROI 2025 Abstract eBook

Abstract eBook

Oral Abstracts

117

Maternal Tenofovir Prophylaxis With Active Immunization to Prevent Infant Hepatitis B Gonzague Jourdain 1 , Nicole Ngo-Giang-Huong 2 , Camlin Tierney 3 , Nicolas Salvadori 1 , Mauricio Pinilla 3 , Touy Chanthalangsy 4 , Soukdalay Sengsilivanh 5 , Khamla Choumlivong 6 , Jullapong Achalapong 7 , Prateung Liampongsabuddhi 8 , Pra-Ornsuda Sukrakanchana 1 , Suriyan Tanasri 1 , Stanislas Pol 9 , Valy Keoluangkhot 5 , Suchada Jiamsiri 10 , for the iTAP Study Group 1 Chiang Mai University, Chiang Mai, Thailand, 2 French National Research Institute for Sustainable Development, Marseille, France, 3 Harvard TH Chan School of Public Health, Boston, MA, USA, 4 Mother and Newborn Hospital, Vientiane, Laos, 5 Mahosot Central Hospital, Vientiane, Laos, 6 Setthathirath Hospital, Vientiane, Laos, 7 Chiang Rai Prachanukroh Hospital, Chiang Rai, Thailand, 8 Lampang Hospital, Lampang, Thailand, 9 Cochin Hospital, Paris, France, 10 Ministry of Public Health, Nonthaburi, Thailand Background: Hepatitis B (HB) vaccination starting with a birth dose and HB immune globulin (HBIg) are given to prevent HB in infants, but HBIg is not available in many settings. This trial aimed to assess whether the risk of infection is below 2% in infants born to HBeAg positive mothers prescribed tenofovir disoproxil fumarate (TDF) prophylaxis, with the infants receiving HB vaccination according to national guidelines without HBIg. This is the regimen recommended by the 2024 WHO Guidelines. Methods: This prospective, single arm clinical trial was designed to enroll 499 pregnant women with positive HBsAg and HBeAg tests at 28 weeks gestational age (GA), no contraindications to TDF, and no HIV infection in 8 public hospitals in Laos and 12 in Thailand (NICHD R01 HD092527) . An HBV DNA load measurement was scheduled during pregnancy to assess adherence and consider infant HBIg if needed. The primary outcome was infant HBV infection (positive HBsAg test confirmed by HBV DNA PCR at 6 months of age). The primary analysis was performed in infants who had an HBsAg test at 6 months of age, who did not receive HBIg, and whose mothers had no evidence of an unsatisfactory virologic response after initiating TDF, defined as HBV DNA load measurement between 20 days after starting TDF and 36 weeks GA that had not decreased by >10-fold in IU/mL from baseline and was >200,000 IU/mL. The proportion of pregnancies with HBV infection at 6 months was estimated along with a two-sided 90% Clopper-Pearson confidence interval (CI). Results: Baseline and follow up data are summarized in the Table. No safety concerns were identified. There were 6 infant deaths, none deemed related to TDF exposure. In the primary analysis, 4 singleton infants of 423 pregnancies were infected at 6 months, yielding an infection risk of 0.95% (90% CI: 0.32%-2.15%), with the upper limit above the 2% hypothesized. In addition, one infant had a first HBsAg positive test (confirmed by HBV DNA PCR) at 4 months but was then lost to follow up, and another was infected but with an unsatisfactory maternal response: both cases were part of those excluded from the primary analysis. Sensitivity analyses confirmed the findings. Conclusions: Maternal TDF prophylaxis and active immunization was efficacious in preventing HBV infection but the risk of infection was not demonstrably below 2%. These findings highlight the level of efficacy achievable when adhering to the 2024 WHO guidelines in South East Asia.

Oral Abstracts

118

Efficacy of Home Visits for Pregnant Couples to Promote Couple HIV Testing and Family Health Lynae Darbes 1 , Zachary A. Kwena 2 , Kevin Owuor 3 , Abigail Hatcher 4 , Anna Helova 3 , Thomas Braun 1 , Evelyne Owengah 2 , Moses Okombo 5 , Van Nghiem 3 , Harsha Thirumurthy 6 , Elizabeth A. Bukusi 7 , Janet M. Turan 3 1 University of Michigan, Ann Arbor, MI, USA, 2 Kenya Medical Research Institute-UCSF Infectious Disease Research Training Program, Kisumu, Kenya, 3 University of Alabama at Birmingham, Birmingham, AL, USA, 4 University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, 5 KEMRI Kenya, Nairobi, Kenya, 6 University of Pennsylvania, Philadelphia, PA, USA, 7 Kenya Medical Research Institute, Kilifi, Kenya Background: Facilitating engagement from both partners of a pregnant couple has the potential to improve joint decision-making, healthcare utilization, and health outcomes. We tested the efficacy of a home-based couples intervention for improving Couples HIV Testing and Counseling (CHTC) and family health during pregnancy and postpartum. Methods: In a 3-arm randomized controlled trial in southwestern Kenya (2019-2024), we recruited women attending antenatal care (2/3 with HIV), subsequently contacting the male partner. A total of 800 pregnant couples were randomized to the home visit intervention (HV, n=267), HIV self-test kits (HIVST, n=266), or standard care (SC, n=267). In the HV arm, lay health worker pairs (one female, one male) conducted 5 couple home visits during pregnancy and postpartum, including health education and couple relationship skills, with CHTC offered at home. Even when women knew their HIV status, CHCT was used to facilitate mutual HIV-status disclosure. In the HIVST arm, pairs of self-test kits were given to the woman to use independently with her partner. Interviews with both partners were conducted in pregnancy and at months 3 and 12 postpartum. Viral loads were abstracted from medical records. Outcomes were analyzed using general estimating equation models, adjusted for previous couple testing, education, wealth, couple age disparity, and length of relationship. Results: Couples in the HV arm had a higher likelihood of engaging in CHTC compared to SC counterparts (adjusted risk ratio (aRR)=4.22, 95% confidence interval (CI)=2.88-6.18), as did those in HIVST arm (aRR=3.69, 95% CI=2.50 5.45). Home visits were associated with a greater number of male HIV+ diagnoses and identification of discordant couples. Measures of positive relationship dynamics (relationship satisfaction, trust, communication) were significantly higher in HV arm compared to HIVST and SC arms. Utilization of maternal and child health services was equally high across the three arms. Only 2 infant HIV infections were detected in the cohort. Women with HIV in HV arm had a significantly higher probability of achieving viral suppression at 18 months (aRR=1.07, 95%CI=1.03-1.12). Conclusions: A home-based couples intervention led to measurable improvements in maternal viral suppression and was associated with increased couple HIV testing and better couple relationships. Addressing both members of a couple around the time of pregnancy is a highly promising strategy for achieving HIV prevention and family health.

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CROI 2025