Prevalence of Urogenital Mycoplasma genitalium Infection at 2 US Army Medical Facilities.

BACKGROUND: Sexually transmitted infections (STIs) have a high incidence in the US Armed Forces and can adversely impact service members' ability to perform their duties. Better knowledge of Mycoplasma genitalium (MG) epidemiology in the military is needed to understand the potential impact of this emerging pathogen on force readiness. METHODS: We conducted cross-sectional analyses of data from US Army service members and other Military Health System beneficiaries participating in a trial of an STI/HIV behavioral intervention at Fort Liberty, NC, and Joint Base Lewis-McChord, WA. At enrollment, participants completed questionnaires and provided biological specimens for nucleic acid amplification testing for MG, Chlamydia trachomatis (CT), and Neisseria gonorrhoeae (NG). We used principal component analysis and robust Poisson regression to examine associations between participant characteristics and prevalent urogenital MG. RESULTS: Among 432 participants enrolled between November 2020 and February 2023, 43 had MG (prevalence, 10.0%), of whom 13 had coinfection with another bacterial STI (all 13 were positive for CT, with 1 also positive for NG). The prevalence of MG was significantly higher among female (13.5%) versus male (7.6%; P = 0.048) participants and non-Hispanic Black (14.9%) versus non-Hispanic White participants (6.6%; P = 0.045). Single relationship status and increased number of recent sexual partners were correlated, and their component was associated with higher MG prevalence (adjusted prevalence ratio, 2.11; 95% confidence interval, 1.29-3.48). CONCLUSIONS: The high prevalence of urogenital MG among Military Health System beneficiaries highlights the importance of understanding the potential clinical sequelae of MG and conducting additional epidemiologic research in military settings.

Paradoxically Greater Persistence of HIV RNA-Positive Cells in Lymphoid Tissue When ART Is Initiated in the Earliest Stage of Infection.

Starting antiretroviral therapy (ART) in Fiebig 1 acute HIV infection limits the size of viral reservoirs in lymphoid tissues, but does not impact time to virus rebound during a treatment interruption. To better understand why the reduced reservoir size did not increase the time to rebound we measured the frequency and location of HIV RNA+ cells in lymph nodes from participants in the RV254 acute infection cohort. HIV RNA+ cells were detected more frequently and in greater numbers when ART was initiated in Fiebig 1 compared to later Fiebig stages and were localized to the T-cell zone compared to the B-cell follicle with treatment in later Fiebig stages. Variability of virus production in people treated during acute infection suggests that the balance between virus-producing cells and the immune response to clear infected cells rapidly evolves during the earliest stages of infection. Clinical Trials Registration: NCT02919306.

Individual Differences in CD4/CD8 T-Cell Ratio Trajectories and Associated Risk Profiles Modeled From Acute HIV Infection.

OBJECTIVE: We examined individual differences in CD4/CD8 T-cell ratio trajectories and associated risk profiles from acute HIV infection (AHI) through 144 weeks of antiretroviral therapy (ART) using a data-driven approach. METHODS: A total of 483 AHI participants began ART during Fiebig I-V and completed follow-up evaluations for 144 weeks. CD4+, CD8+, and CD4/CD8 T-cell ratio trajectories were defined followed by analyses to identify associated risk variables. RESULTS: Participants had a median viral load (VL) of 5.88 copies/ml and CD4/CD8 T-cell ratio of 0.71 at enrollment. After 144 weeks of ART, the median CD4/CD8 T-cell ratio was 1.3. Longitudinal models revealed five CD4/CD8 T-cell ratio subgroups: group 1 (3%) exhibited a ratio >1.0 at all visits; groups 2 (18%) and 3 (29%) exhibited inversion at enrollment, with normalization 4 and 12 weeks after ART, respectively; and groups 4 (31%) and 5 (18%) experienced CD4/CD8 T-cell ratio inversion due to slow CD4+ T-cell recovery (group 4) or high CD8+ T-cell count (group 5). Persistent inversion corresponded to ART onset after Fiebig II, higher VL, soluble CD27 and TIM-3, and lower eosinophil count. Individuals with slow CD4+ T-cell recovery exhibited higher VL, lower white blood cell count, lower basophil percent, and treatment with standard ART, as well as worse mental health and cognition, compared with individuals with high CD8+ T-cell count. CONCLUSIONS: Early HIV disease dynamics predict unfavorable CD4/CD8 T-cell ratio outcomes after ART. CD4+ and CD8+ T-cell trajectories contribute to inversion risk and correspond to specific viral, immune, and psychological profiles during AHI. Adjunctive strategies to achieve immune normalization merit consideration.

Attitudes About Analytic Treatment Interruption (ATI) in HIV Remission Trials with Different Antiretroviral Therapy (ART) Resumption Criteria.

HIV remission trials often require temporary stopping of antiretroviral therapy (ART)-an approach called analytic treatment interruption (ATI). Trial designs resulting in viremia raise risks for participants and sexual partners. We conducted a survey on attitudes about remission trials, comparing ART resumption criteria (lower-risk "time to rebound" and higher-risk "sustained viremia") among participants from an acute HIV cohort in Thailand. Analyses included Wilcoxon-Ranks and multivariate logistic analysis. Most of 408 respondents supported ATI trials, with slightly higher approval of, and willingness to participate in, trials using time to rebound versus sustained viremia criteria. Less than half of respondents anticipated disclosing trial participation to partners and over half indicated uncertainty or unwillingness about whether partners would be willing to use PrEP. Willingness to participate was higher among those who rated higher trial approval, lower anticipated burden, and those expecting to make the decision independently. Our findings support acceptability of ATI trials among most respondents. Participant attitudes and anticipated behaviors, especially related to transmission risk, have implications for future trial design and informed consent.

Persons living with HIV treated in acute HIV infection report good health-related quality of life in Thailand.

The health-related quality of life (HRQoL) among persons living with HIV (PLWHA) who initiate ART during acute HIV infection (AHI) is not well studied. Participants in the SEARCH010/RV254 cohort initiated ART during AHI. They completed the Thai version of the World Health Organisation Quality of Life instrument-BREF (WHOQOL-BREF) and Patient Health Questionnaire-9 (PHQ-9) prior to ART initiation and 24 weeks later. Of 452 participants, 406 (90%) completed the WHOQOL-BREF. The median age was 26 years (IQR 22-31), and 98% were men. All WHOQOL-BREF domains demonstrated good internal consistency (Cronbach's alpha >0.70). Confirmatory factor analysis validated the WHOQOL-BREF model. 90% of Pearson correlations between domain scores and general facet items were >0.50. HRQoL in all domains was worse among those with at least moderately severe depression (PHQ-9 ≥ 10) (p<0.0001), supporting discriminant validity. At 24 weeks, there was an improvement of scores in all domains (physical, psychological, social, and environmental) and general facet items (p<0.0001), and the range of mean domain scores was 14.7-15.6 (SD 2.3-2.8). The majority of participants (58-63%) had improved HRQoL in the physical, psychological and environmental domains. It is concluded that HRQoL improves 6 months after initiation of ART in AHI, suggesting a benefit of early ART initiation.

Feasibility, acceptability, and short-term impact of a brief sexually transmitted infection intervention targeting U.S. Military personnel and family members.

BACKGROUND: Over the past 10 years, incidence of sexually transmitted infections (STIs) has increased to record numbers in the United States, with the most significant increases observed among adolescents and young adults. The US military, where the majority of active duty personnel are 18-30 years old, has seen similar increases. However, the US military does not yet have a standardized, service-wide program for STI education and prevention. METHODS: The KISS intervention (Knocking out Infections through Safer-sex and Screening) was adapted from an evidence-based intervention endorsed by the US Centers for Disease Control and Prevention and consisted of a one-time, small group session. Content included STI/HIV knowledge and prevention, condom use skills, and interpersonal communication techniques. The intervention was pilot tested for feasibility and acceptability among a population of service members and medical beneficiaries at Joint Base Lewis-McChord in Washington state. RESULTS: A total of 79 participants aged 18-30 years were consented to participate in the pilot study and met entry criteria, 66/79 (82.5%) attended the intervention session, and 46/66 (69.7%) returned at 3 months for the final follow-up assessment. The intervention sessions included 31 male (47.0%) and 35 female (53.0%) participants. Almost all participants felt comfortable discussing sexual issues in the group sessions, reported that they intended to practice safer sex after the intervention, and would also recommend the intervention to friends. Knowledge about STI/HIV prevention significantly increased after the intervention, and intervention effects were maintained at 3 months. About one-fifth of participants tested positive for N. gonorrhea or C. trachomatis infection at enrollment, while none had recurrent STIs at the final visit. Use of both male and female condoms increased after the intervention. CONCLUSIONS: The KISS intervention was feasible to implement in the military setting and was acceptable to the active duty service members and other medical beneficiaries who participated in the pilot project. Further studies are needed to determine if the KISS intervention, or others, effectively decrease STI incidence in active duty personnel and would be appropriate for more widespread implementation. TRIAL REGISTRATION: Retrospectively registered as the pilot phase of clinicaltrials.gov NCT04547413 , "Prospective Cohort Trial to Assess Acceptability and Efficacy of an Adapted STI/HIV Intervention Behavioral Intervention Program in a Population of US Army Personnel and Their Medical Beneficiaries-Execution Phase."

Central Nervous System Safety During Brief Analytic Treatment Interruption of Antiretroviral Therapy Within 4 Human Immunodeficiency Virus Remission Trials: An Observational Study in Acutely Treated People Living With Human Immunodeficiency Virus.

BACKGROUND: The central nervous system (CNS) is a likely reservoir of human immunodeficiency virus (HIV), vulnerable to viral rebound, inflammation, and clinical changes upon stopping antiretroviral therapy (ART). It is critical to evaluate the CNS safety of studies using analytic treatment interruption (ATI) to assess HIV remission. METHODS: Thirty participants who started ART during acute HIV infection underwent CNS assessments across 4 ATI remission trials. ART resumption occurred with plasma viral load >1000 copies/mL. CNS measures included paired pre- vs post-ATI measures of mood, cognitive performance, and neurologic examination, with elective cerebrospinal fluid (CSF) sampling, brain diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS). RESULTS: Median participant age was 30 years old and 29/30 were male. Participants' median time on ART before ATI was 3 years, and ATI lasted a median of 35 days. Post-ATI, there were no differences in median mood scores or neurologic findings and cognitive performance improved modestly. During ATI, a low level of CSF HIV-1 RNA was detectable in 6 of 20 participants with plasma viremia, with no group changes in CSF immune activation markers or brain DTI measures. Mild worsening was identified in post-ATI basal ganglia total choline MRS, suggesting an alteration in neuronal membranes. CONCLUSION: No adverse CNS effects were observed with brief, closely monitored ATI in participants with acutely treated HIV, except an MRS alteration in basal ganglia choline. Further studies are needed to assess CNS ATI safety in HIV remission trials, particularly for studies using higher thresholds to restart ART and longer ATI durations.

Viral Blips After Treatment Initiation During Acute Human Immunodeficiency Virus Infection.

Transient viral blips ≥20 copies/mL were observed in 16.9% of acutely treated adults with HIV. Blip incidence increased from 0.0 (95% CI, 0.0-2.9)/100 person-years after ART in Fiebig I to 15.9 (7.6-29.2) in Fiebig V. Increasing viral load and Fiebig stage at ART initiation were independently predictive of blips.

Large transmission cluster of acute hepatitis C identified among HIV-positive men who have sex with men in Bangkok, Thailand.

A rapidly emerging and highly concentrated hepatitis C virus (HCV) outbreak has recently been observed among both acute and chronic HIV-positive men who have sex with men (MSM) in Bangkok, Thailand. NS5B regions of the HCV genome were amplified using nested PCR and sequenced. Phylogenetic inference was constructed by Maximum Likelihood methods and clusters were identified with support and genetic distance thresholds of 85% and of 4.5%. Forty-eight (25 acute HIV and 23 chronic HIV) MSM with incident HCV infection were included in the analysis. HCV genotype (GT) was 85% GT 1a and 15% GT 3a or 3b. Median age at HCV diagnosis was 34 (interquartile range, 28-41) years. 83.3% (40/48) had history of syphilis infection and 36% (16/44) reported crystal methamphetamine use. Only 2 (4%) reported ever injecting drugs, both crystal methamphetamine. In the phylogenetic clustering analysis, 83% belonged to one of two clusters: one large (75%) and one small (8%) cluster. All clusters were GT 1a. MSM with acute HIV infection were more likely to be in a cluster (92%) than those with chronic infection (74%). HCV screening should be regularly performed for MSM in ART clinics, and offering direct-acting antiviral agents to all MSM with HCV infection might contain the HCV epidemic from expanding further.

Impact of Early Antiretroviral Therapy on Detection of Cell-Associated HIV-1 Nucleic Acid in Blood by the Roche Cobas TaqMan Test.

The Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 test, v2.0 (the CAP/CTM assay), was used to quantify cell-associated HIV-1 (CAH) nucleic acid in peripheral blood mononuclear cells (PBMC) from well-characterized clinical specimens from HIV-1-infected individuals on antiretroviral therapy (ART). Chronically infected individuals on ART with no detectable plasma HIV-1 RNA demonstrated average CAH burdens of 3.2 HIV-1 log10 copies/million cells. Assay sensitivity and specificity were 98.9% and 100%, respectively, with the positive and negative predictive values being 100% and 98.6%, respectively. The CAH burden was also measured at weeks 0, 1, 2, 8, and 60 in 37 participants (RV254/SEARCH010, Bangkok, Thailand) stratified by Fiebig stage (Fiebig stage I [FI] to FVI) at ART initiation. Prior to ART initiation, the average CAH burden was 1.4, 4.1, and 3.6 log10 copies/million PBMCs for individuals who initiated ART at FI, FII, and FIII to FVI, respectively. Initiation of ART resulted in a rapid decline of CAH in all individuals, with the greatest decrease being observed in individuals who initiated ART at FI to FIII. By week 60, 100% (FI), 71.8% (FII/FIII), and 20.5% (FIV to FVI) of samples from individuals initiating treatment were at or near the limit of quantitation. Residual CAH was detectable at 60 weeks in most individuals who initiated ART at later stages (FIV to FVI) and averaged 1.9 ± 0.7 log10 copies/million PBMCs. The modified Roche CAP/CTM assay provides a convenient, standardized approach to measure residual HIV in blood and may be useful for monitoring patients under therapy or those participating in HIV remission studies.

Leveraging early HIV diagnosis and treatment in Thailand to conduct HIV cure research.

Thailand has the highest prevalence of HIV among countries in Asia but has also been a pioneer in HIV prevention and treatment efforts in the region, reducing the incidence of new infections significantly over the last two decades. Building upon this remarkable history, Thailand has set an ambitious goal to stop the AIDS epidemic in the country by 2030. A key component of the strategy to achieve this goal includes scale-up of HIV screening programs to facilitate early HIV diagnosis and investment in mechanisms to support immediate initiation of antiretroviral therapy (ART). Initiation of ART during early or acute HIV infection not only reduces viremia, thereby halting onward transmission of HIV, but also may facilitate HIV remission by reducing the size of the latent HIV reservoir and preserving immune function. In Thailand, many efforts have been made to reduce the time from HIV infection to diagnosis and from diagnosis to treatment, especially among men who have sex with men and transgender women. Successfully identifying and initiating ART in individuals with acute HIV infection has been leveraged to conduct groundbreaking studies of novel strategies to achieve HIV remission, including studies of broadly-neutralizing HIV-specific monoclonal antibodies and candidate therapeutic vaccines. These efforts have mostly been deployed in Bangkok and future efforts should include other urban and more rural areas. Continued progress in HIV prevention, screening, and treatment will position Thailand to substantially limit new infections and may pave the way for an HIV cure.

Distribution of Human Immunodeficiency Virus (HIV) Ribonucleic Acid in Cerebrospinal Fluid and Blood Is Linked to CD4/CD8 Ratio During Acute HIV.

Background: Human immunodeficiency virus (HIV) ribonucleic acid (RNA) levels in the plasma and cerebrospinal fluid (CSF) are correlated in chronic HIV infection, but their dynamics have not been characterized during acute infection. Methods: This study analyzed predictors of CSF HIV RNA and relative degree of CNS viral transmigration expressed as plasma minus CSF HIV log10 RNA (PCratio) during untreated acute HIV infection. Cerebrospinal fluid immune markers were compared between groups with different PCratio. Results: One hundred seventeen mostly male (97%) participants in the RV254 cohort in Bangkok, Thailand, had a median age of 28 years and an estimated median 18 days duration of infection; 43 (37%) were Fiebig stages I/II. Twenty-seven (23%) had CSF HIV RNA <80 copies/mL. Those with quantifiable levels (n = 90) had median CSF HIV RNA and PCratio of 3.76 and 2.36 log10 copies/mL, respectively. Human immunodeficiency virus RNA peaked at Fiebig III in plasma and Fiebig IV in CSF. In multivariable analyses, plasma HIV RNA and CD4/CD8 ratio independently correlated with CSF HIV RNA (P < .001), whereas CD4/CD8 ratio predicted PCratio (P = .018). Participants with PCratio <1 had higher CSF neopterin, soluble (s)CD163, interleukin-6, and sCD14 levels (all P < .05). Conclusions: CD4/CD8 ratio independently correlated with CSF HIV RNA and PCratio, suggesting that immune responses modulate central nervous system viral entry at early infection.

Acquisition of Multidrug-Resistant Human Immunodeficiency Virus Type 1 Infection in a Patient Taking Preexposure Prophylaxis.

We report a case indicating that acquisition of multidrug-resistant human immunodeficiency (HIV) virus type 1 during preexposure prophylaxis with combination tenofovir disoproxil fumarate and emtricitabine or evolution of resistance after HIV seroconversion remains a risk.

Acute Retroviral Syndrome Is Associated With High Viral Burden, CD4 Depletion, and Immune Activation in Systemic and Tissue Compartments.

Background: Many individuals with acute human immunodeficiency virus infection (AHI) experience acute retroviral syndrome (ARS), which is associated with adverse long-term clinical outcomes. Methods: Participants presenting for voluntary human immunodeficiency virus (HIV) testing were enrolled during AHI in Bangkok, Thailand. ARS was defined by ≥3 qualifying signs/symptoms. HIV burden, immunophenotypes, and biomarkers were stratified by ARS diagnosis at enrollment and after up to 96 weeks of antiretroviral therapy (ART). Results: From 212382 samples screened, 430 participants were enrolled during AHI, including 335 (78%) with ARS. Median age was 26 years and 416 (97%) were men. Sixty (14%) underwent sigmoid biopsy and 105 (24%) underwent lumbar puncture during AHI. Common symptoms included fever (93%), fatigue (79%), pharyngitis (67%), and headache (64%). Compared to those without ARS, participants with ARS were in later Fiebig stages with higher HIV RNA in blood, colon, and cerebrospinal fluid; higher total HIV DNA in blood; CD4 depletion in blood and colon; and elevated plasma tumor necrosis factor alpha (TNF-α), C-reactive protein, and D-dimer (all P < .05). Subgroup analyses of Fiebig I/II participants (95 with ARS, 69 without) demonstrated similar findings. After 96 weeks of ART, TNF-α and interleukin 6 were elevated in the ARS group (P < .05) but other biomarkers equilibrated. Conclusions: ARS was associated with high viral burden, CD4 depletion, and immune activation across multiple body compartments during AHI and prior to ART. Persistent inflammation despite suppressive ART could contribute to increased morbidity in individuals who experience ARS.

Altered Memory Circulating T Follicular Helper-B Cell Interaction in Early Acute HIV Infection.

The RV254 cohort of HIV-infected very early acute (4thG stage 1 and 2) (stage 1/2) and late acute (4thG stage 3) (stage 3) individuals was used to study T helper- B cell responses in acute HIV infection and the impact of early antiretroviral treatment (ART) on T and B cell function. To investigate this, the function of circulating T follicular helper cells (cTfh) from this cohort was examined, and cTfh and memory B cell populations were phenotyped. Impaired cTfh cell function was observed in individuals treated in stage 3 when compared to stage 1/2. The cTfh/B cell cocultures showed lower B cell survival and IgG secretion at stage 3 compared to stage 1/2. This coincided with lower IL-10 and increased RANTES and TNF-α suggesting a role for inflammation in altering cTfh and B cell responses. Elevated plasma viral load in stage 3 was found to correlate with decreased cTfh-mediated B cell IgG production indicating a role for increased viremia in cTfh impairment and dysfunctional humoral response. Phenotypic perturbations were also evident in the mature B cell compartment, most notably a decrease in resting memory B cells in stage 3 compared to stage 1/2, coinciding with higher viremia. Our coculture assay also suggested that intrinsic memory B cell defects could contribute to the impaired response despite at a lower level. Overall, cTfh-mediated B cell responses are significantly altered in stage 3 compared to stage 1/2, coinciding with increased inflammation and a reduction in memory B cells. These data suggest that early ART for acutely HIV infected individuals could prevent immune dysregulation while preserving cTfh function and B cell memory.

HIV, Hepatitis C, and Other Sexually Transmitted Infections Among Male Sex Workers in Ho Chi Minh City, Vietnam.

There is little data on the burden of HIV and other infections that affect male sex workers (MSW) in Vietnam. We conducted behavioral and biological sexual health surveys with 300 MSW in Ho Chi Minh City. Generalized estimating equation models were built to assess factors associated with HIV, hepatitis C, and other sexually transmitted infections (STI). Of 300 MSW, 19 (6.3 %) were diagnosed seropositive for HIV, 11 (3.7 %) had hepatitis C, and 26 (8.7 %) had at least one prevalent STI. In a multivariable model, opiate use was significantly associated with HIV infection (aOR 6.46, 95 % CI 1.28-32.7) and hepatitis C (aOR = 19.6, 95 % CI 2.35-163.6). Alcohol dependency was associated with increased odds of hepatitis C (aOR = 4.79, 95 % CI 1.02-22.5) and decreased odds of other STI (aOR = 0.30, 95 % CI 0.10-0.97). These findings suggest that MSW in Vietnam would benefit from regular HIV and STI testing, as well as linkage to care and substance use rehabilitation services.

Correlates of HIV Testing Among Transgender Women in Ho Chi Minh, Vietnam.

HIV prevalence among transgender women (TW) in Ho Chi Minh City is estimated at 18 %. However, no evidence-based programs or surveillance data exist in Vietnam specific to HIV testing uptake. We examined prevalence and correlates of past-year HIV testing among TW (n = 204) recruited in 2015 via snowball sampling. 59.3 % reported HIV testing in the previous year. In adjusted models, factors positively associated with HIV testing included consistent condom use during sex work with male clients; STI testing in past year; sex with casual partners in the past month; and experiences of police harassment. Factors negatively associated with recent HIV testing included daily/weekly alcohol use and post-traumatic stress symptoms. This study found significant associations between greater safety in sexual behaviors and higher rates of HIV testing. Targeted and specific services are needed for TW in Vietnam in order to address sexual risk behaviors and provide appropriate access to regular HIV testing.

A Group-Based Sexual Risk Reduction Intervention for Men Who Have Sex With Men in Ho Chi Minh City, Vietnam: Feasibility, Acceptability, and Preliminary Efficacy.

An emerging HIV epidemic can be seen among men who have sex with men (MSM) in Vietnam. There are currently no evidence-based behavioral sexual risk reduction interventions for MSM in this setting. Between October 2012 and June 2013, 100 high-risk MSM from Ho Chi Minh City were enrolled in an open pilot trial to assess feasibility and acceptability of a group-based, manualized sexual risk reduction intervention, and to preliminarily examine changes in primary and secondary outcomes. Participants completed a behavioral assessment battery and HIV testing at baseline, 3, and 6 months post-baseline. Over 80.0 % of the sample was <25 years old and 77.0 % identified as Bong kin ("hidden," masculine-appearing). Feasibility and acceptability of the program was evidenced by 87.0 % retention for the intervention sessions, 78.0 % completion of the 6 month assessment, and positive responses on evaluation forms and qualitative exit interviews. There was a decline in the number of condomless anal sex acts from baseline (6.32) to 3 month (2.06) and 6 month (2.49) follow-up (p < .0001). These data support the need for further testing of this group-based, behavioral HIV prevention intervention to reduce sexual risk behavior among MSM in Vietnam in a randomized controlled efficacy trial.

Mosaic vaccine-induced antibody-dependent cellular phagocytosis associated with delayed HIV-1 viral load rebound post treatment interruption.

A heterologous Ad26/MVA vaccine was given prior to an analytic treatment interruption (ATI) in people living with HIV-1 (mainly CRF01_AE) who initiated antiretroviral treatment (ART) during acute HIV-1. We investigate the impact of Ad26/MVA vaccination on antibody (Ab)-mediated immune responses and their effect on time to viral rebound. The vaccine mainly triggers vaccine-matched binding Abs while, upon viral rebound post ATI, infection-specific CRF01_AE binding Abs increase in all participants. Binding Abs are not associated with time to viral rebound. The Ad26/MVA mosaic vaccine profile consists of correlated non-CRF01_AE binding Ab and Fc effector features, with strong Ab-dependent cellular phagocytosis (ADCP) responses. CRF01_AE-specific ADCP responses (measured either prior to or post ATI) are significantly higher in individuals with delayed viral rebound. Our results suggest that vaccines eliciting cross-reactive responses with circulating viruses in a target population could be beneficial and that ADCP responses may play a role in viral control post treatment interruption.