HIV-1 remission and possible cure in a woman after haplo-cord blood transplant.

Previously, two men were cured of HIV-1 through CCR5Δ32 homozygous (CCR5Δ32/Δ32) allogeneic adult stem cell transplant. We report the first remission and possible HIV-1 cure in a mixed-race woman who received a CCR5Δ32/Δ32 haplo-cord transplant (cord blood cells combined with haploidentical stem cells from an adult) to treat acute myeloid leukemia (AML). Peripheral blood chimerism was 100% CCR5Δ32/Δ32 cord blood by week 14 post-transplant and persisted through 4.8 years of follow-up. Immune reconstitution was associated with (1) loss of detectable replication-competent HIV-1 reservoirs, (2) loss of HIV-1-specific immune responses, (3) in vitro resistance to X4 and R5 laboratory variants, including pre-transplant autologous latent reservoir isolates, and (4) 18 months of HIV-1 control with aviremia, off antiretroviral therapy, starting at 37 months post-transplant. CCR5Δ32/Δ32 haplo-cord transplant achieved remission and a possible HIV-1 cure for a person of diverse ancestry, living with HIV-1, who required a stem cell transplant for acute leukemia.

Emergency myelopoiesis distinguishes multisystem inflammatory syndrome in children from pediatric severe COVID-19.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a hyperinflammatory condition caused by recent SARS-CoV-2 infection, but the underlying immunological mechanisms driving this distinct syndrome are unknown. METHODS: We utilized high dimensional flow cytometry, cell-free (cf) DNA, and cytokine and chemokine profiling to identify mechanisms of critical illness distinguishing MIS-C from severe acute COVID-19 (SAC). RESULTS: Compared to SAC, MIS-C patients demonstrated profound innate immune cell death and features of emergency myelopoiesis (EM), an understudied phenomenon observed in severe inflammation. EM signatures were characterized by fewer mature myeloid cells in the periphery and decreased expression of HLA-DR and CD86 on antigen presenting cells. IL-27, a cytokine known to drive hematopoietic stem cells towards EM, was increased in MIS-C, and correlated with immature cell signatures in MIS-C. Upon recovery, EM signatures decreased, and IL-27 plasma levels returned to normal levels. Despite profound lymphopenia, we report a lack of cfDNA released by adaptive immune cells and increased CCR7 expression on T cells indicative of egress out of peripheral blood. CONCLUSIONS: Immune cell signatures of EM combined with elevated innate immune cell-derived cfDNA levels distinguish MIS-C from SAC in children and provide mechanistic insight into dysregulated immunity contributing towards MIS-C, offering potential diagnostic and therapeutic targets.

Infants Receiving Very Early Antiretroviral Therapy Have High CD4 Counts in the First Year of Life.

We followed 54 infants with in utero HIV after initiating very early antiretroviral treatment. At weeks 24 and 48, ≥80% had CD4 ≥1500 cells/mm3 and CD4% ≥25%. Routine Pneumocystis jirovecii pneumonia prophylaxis in the first year of life may not be necessary for all very early treated infants. CLINICAL TRIALS REGISTRATION: NCT02140255.

Extended Analysis of HIV Infection in Cisgender Men and Transgender Women Who Have Sex with Men Receiving Injectable Cabotegravir for HIV Prevention: HPTN 083.

HPTN 083 demonstrated that injectable cabotegravir (CAB) was superior to oral tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) for HIV prevention in cisgender men and transgender women who have sex with men. We previously analyzed 58 infections in the blinded phase of HPTN 083 (16 in the CAB arm and 42 in the TDF-FTC arm). This report describes 52 additional infections that occurred up to 1 year after study unblinding (18 in the CAB arm and 34 in the TDF-FTC arm). Retrospective testing included HIV testing, viral load testing, quantification of study drug concentrations, and drug resistance testing. The new CAB arm infections included 7 with CAB administration within 6 months of the first HIV-positive visit (2 with on-time injections, 3 with ≥1 delayed injection, and 2 who restarted CAB) and 11 with no recent CAB administration. Three cases had integrase strand transfer inhibitor (INSTI) resistance (2 with on-time injections and 1 who restarted CAB). Among 34 CAB infections analyzed to date, diagnosis delays and INSTI resistance were significantly more common in infections with CAB administration within 6 months of the first HIV-positive visit. This report further characterizes HIV infections in persons receiving CAB preexposure prophylaxis and helps define the impact of CAB on the detection of infection and the emergence of INSTI resistance.

Characterization of Human Immunodeficiency Virus (HIV) Infections in Women Who Received Injectable Cabotegravir or Tenofovir Disoproxil Fumarate/Emtricitabine for HIV Prevention: HPTN 084.

BACKGROUND: HIV Prevention Trials Network 084 demonstrated that long-acting injectable cabotegravir (CAB) was superior to daily oral tenofovir (TFV) disoproxil fumarate (TDF)/emtricitabine (FTC) for preventing human immunodeficiency virus (HIV) infection in sub-Saharan African women. This report describes HIV infections that occurred in the trial before unblinding. METHODS: Testing was performed using HIV diagnostic assays, viral load testing, a single-copy RNA assay, and HIV genotyping. Plasma CAB, plasma TFV, and intraerythrocytic TFV-diphosphate concentrations were determined by liquid chromatography-tandem mass spectrometry. RESULTS: Forty HIV infections were identified (CAB arm, 1 baseline infection, 3 incident infections; TDF/FTC arm, 36 incident infections). The incident infections in the CAB arm included 2 with no recent drug exposure and no CAB injections and 1 with delayed injections; in 35 of 36 cases in the TDF/FTC arm, drug concentrations indicated low or no adherence. None of the cases had CAB resistance. Nine women in the TDF/FTC arm had nonnucleoside reverse-transcriptase inhibitor resistance; 1 had the nucleoside reverse-transcriptase inhibitor resistance mutation, M184V. CONCLUSIONS: Almost all incident HIV infections occurred in the setting of unquantifiable or low drug concentrations. CAB resistance was not detected. Transmitted nonnucleoside reverse-transcriptase inhibitor resistance was common; 1 woman may have acquired nucleoside reverse-transcriptase inhibitor resistance from study drug exposure.

Distinct Cytokine and Chemokine Dysregulation in Hospitalized Children With Acute Coronavirus Disease 2019 and Multisystem Inflammatory Syndrome With Similar Levels of Nasopharyngeal Severe Acute Respiratory Syndrome Coronavirus 2 Shedding.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a severe clinical phenotype of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that remains poorly understood. METHODS: Hospitalized children <18 years of age with suspected coronavirus disease 2019 (COVID-19) (N = 53) were recruited into a prospective cohort study; 32 had confirmed COVID-19, with 16 meeting the US Centers for Disease Control criteria for MIS-C. Differences in nasopharyngeal viral ribonucleic acid (RNA) levels, SARS-CoV-2 seropositivity, and cytokine/chemokine profiles were examined, including after adjustments for age and sex. RESULTS: The median ages for those with and without MIS-C were 8.7 years (interquartile range [IQR], 5.5-13.9) and 2.2 years (IQR, 1.1-10.5), respectively (P = .18), and nasopharyngeal levels of SARS-CoV-2 RNA did not differ significantly between the 2 groups (median 63 848.25 copies/mL versus 307.1 copies/mL, P = .66); 75% of those with MIS-C were antibody positive compared with 44% without (P = .026). Levels of 14 of 37 cytokines/chemokines (interleukin [IL]-1RA, IL-2RA, IL-6, IL-8, tumor necrosis factor-α, IL-10, IL-15, IL-18, monocyte chemoattractant protein [MCP]-1, IP-10, macrophage-inflammatory protein [MIP]-1α, MCP-2, MIP-1ß, eotaxin) were significantly higher in children with MIS-C compared to those without, irrespective of age or sex (false discovery rate <0.05; P < .05). CONCLUSIONS: The distinct pattern of heightened cytokine/chemokine dysregulation observed with MIS-C, compared with acute COVID-19, occurs across the pediatric age spectrum and with similar levels of nasopharyngeal SARS-CoV-2 RNA.

Characterization of Human Immunodeficiency Virus (HIV) Infection in Cisgender Men and Transgender Women Who Have Sex With Men Receiving Injectable Cabotegravir for HIV Prevention: HPTN 083.

BACKGROUND: The HIV Prevention Trials Network (HPTN) 083 trial demonstrated that long-acting cabotegravir (CAB-LA) was more effective than tenofovir disoproxil fumarate-emtricitabine (TDF/FTC) in preventing human immunodeficiency virus (HIV) in cisgender men and transgender women who have sex with men. We characterized HIV infections that occurred in the blinded phase of HPTN 083. METHODS: Retrospective testing included HIV testing, viral load testing, quantification of study drugs, and HIV drug resistance testing. RESULTS: Fifty-eight infections were evaluated, including 51 incident infections (12 in CAB arm and 39 in TDF/FTC arm). In many cases (5 in CAB arm and 37 in TDF/FTC arm), infection was associated with low or unquantifiable study drug concentrations. In 4 cases, infection occurred with on-time CAB-LA injections and expected plasma CAB concentrations. CAB exposure was associated with prolonged viral suppression and delayed antibody expression. In some cases, delayed HIV diagnosis resulted in CAB provision to participants with undetected infection, delayed antiretroviral therapy, and emergence of drug resistance; most of these infections would have been detected earlier with viral load testing. CONCLUSIONS: Early detection of HIV infection and prompt antiretroviral therapy initiation could improve clinical outcomes in persons who become infected despite CAB-LA prophylaxis. Further studies are needed to elucidate the correlates of HIV protection in persons receiving CAB-LA.

Pediatric HIV: the Potential of Immune Therapeutics to Achieve Viral Remission and Functional Cure.

PURPOSE OF REVIEW: In the absence of antiretroviral therapy (ART), more than 50% of perinatally HIV-infected children die by 2 years of age. Early ART from infancy is therefore a global recommendation and significantly improves immune health, child survival, and disease outcome. However, even early treatment does not prevent or eradicate the latent reservoir necessitating life-long ART. Adherence to life-long ART is challenging for children and longstanding ART during chronic HIV infection led to higher risks of non-AIDS co-morbidities and virologic failure in infected children. Thus, HIV-infected children are an important population for consideration for immune-based interventions to achieve ART-free remission and functional cure. This review summarizes how the uniqueness of the early life immune system can be harnessed for the development of ART-free remission and functional cure, which means complete virus control in absence of ART. In addition, recent advances in therapeutics in the HIV cure field and their potential for the treatment of pediatric HIV infections are discussed. RECENT FINDINGS: Preclinical studies and clinical trials demonstrated that immune-based interventions target HIV replication, limit size of virus reservoir, maintain virus suppression, and delay time to virus rebound. However, these studies have been performed so far only in carefully selected HIV-infected adults, highlighting the need to evaluate the efficacy of immune-based therapeutics in HIV-infected children and to design interventions tailored to the early life maturing immune system. Immune-based therapeutics alone or in combination with ART should be actively explored as potential strategies to achieve viral remission and functional cure in HIV-infected pediatric populations.

The Latent Human Immunodeficiency Virus (HIV) Reservoir Resides Primarily in CD32-CD4+ T Cells in Perinatally HIV-Infected Adolescents With Long-Term Virologic Suppression.

Background: High-level expression of the Fcγ receptor, CD32hi, on CD4+ T cells was associated with enhanced human immunodeficiency virus (HIV) infection of the latent reservoir in a study of adults receiving antiretroviral therapy. We tested the hypothesis that CD32 was the preferential marker of the latent HIV reservoir in virally suppressed, perinatally HIV-infected adolescents. Methods: The frequency of CD32hiCD4+ T cells was determined by flow cytometry (N = 5) and the inducible HIV reservoir in both CD32hi and CD32-CD4+ T cells was quantified (N = 4) with a quantitative viral outgrowth assay. Viral outgrowth was measured by the standard p24 enzyme-linked immunosorbent assay and an ultrasensitive p24 assay (Simoa; Quanterix) with lower limits of quantitation. Results: We found a 59.55-fold enrichment in the absolute number of infectious cells in the CD32- population compared with CD32hi cells. Exponential HIV replication occurred exclusively in CD32-CD4+ T cells (mean change, 17.46 pg/mL; P = .04). Induced provirus in CD32hiCD4+ T cells replicated to substantially lower levels, which did not increase significantly over time (mean change, 0.026 pg/mL; P = .23) and were detected only with the Simoa assay. Conclusions: Our data suggests that the latent HIV reservoir resides mainly in CD32-CD4+ T cells in virally suppressed, perinatally HIV-infected adolescents, which has implications for reservoir elimination strategies.

Quantitative Human Immunodeficiency Virus (HIV)-1 Antibodies Correlate With Plasma HIV-1 RNA and Cell-associated DNA Levels in Children on Antiretroviral Therapy.

BACKGROUND: This study measured serial plasma human immunodeficiency virus (HIV)-1-specific antibody (Ab) levels in children who initiated antiretroviral therapy (ART) prior to 2 years of age, and evaluated their relationship to peripheral blood HIV-1 RNA and DNA levels. METHODS: We studied 46 HIV-1-infected children, stratified by age at ART initiation (<3 mo, early therapy [ET]; >3 mo-2 years, late therapy [LT]) and by virologic response (R) or non-response (NR), before and up to 4 years following ART. We studied 20 HIV-1-uninfected children born to HIV-1-infected mothers (seroreverters [SR]) as controls. Plasma immunoglobulin G (IgG) Ab levels directed against HIV-1 envelope (gp160, gp41), gag (capsid, p24; matrix, p17), reverse transcriptase (p66/51), and integrase (p31) were serially measured using quantitative enzyme-linked immunosorbent assays. HIV-1 Ab rates of decline were estimated over the first 15 months of the study. RESULTS: The HIV-1 Ab rates of decline in the ET-R group were similar to those in the SR group for all Ab specificities, except for p17 (P = .01). Ab decline rates in the LT-R group and the NR group were significantly slower than in the SR group for all tested Ab specificities. After 1 year of age, Ab levels to p31 and p17 were significantly associated with HIV-1 RNA levels (P < .001); Ab levels to gp160 (P < .001) and gp41 (P < .001) were significantly associated with cell-associated HIV-1 DNA levels. CONCLUSIONS: Quantitative HIV-1-specific Ab levels may be useful for screening children on ART for viral suppression or for residual, cell-associated HIV-1 DNA levels. CLINICAL TRIALS REGISTRATION: NCT00000872.

Intestinal Integrity Biomarkers in Early Antiretroviral-Treated Perinatally HIV-1-Infected Infants.

Intestinal fatty acid binding protein (iFABP) levels did not differ between human immunodeficiency virus type 1 (HIV-1)- infected infants and uninfected infants exposed to HIV-1, but those who breastfed had substantially lower levels. Zonulin levels increased from 3 to 5.3 months of age with perinatal acquisition of HIV-1 despite early antiretroviral treatment. Biomarkers of intestinal integrity (ie, iFABP and zonulin) were compared in 56 HIV-1-positive African infants who received early antiretroviral treatment and 53 HIV-1-exposed but uninfected (HEU) controls. Despite heightened inflammation and immune activation in HIV-positive infants, iFABP and zonulin levels at 3 months of age were not different from those in HEU infants and largely were not correlated with inflammatory and immune activation biomarkers. However, zonulin levels increased and became significantly higher in HIV-positive infants as compared to HEU infants by 5 months of age, despite viral suppression due to antiretroviral treatment. These findings have implications for intestinal integrity biomarker profiling in perinatal HIV-1 infection.

CNS Persistence of HIV-1 in Children: the Untapped Reservoir.

PURPOSE OF REVIEW: The central nervous system (CNS) represents a potential HIV-1 reservoir that may need to be specifically targeted by remission strategies. Perinatally HIV-1-infected children and youth are exposed to HIV-1 at a critical period of brain development. This review summarizes the current literature regarding HIV-1 and the CNS in perinatal infection. RECENT FINDINGS: HIV-1-associated encephalopathy is prevalent with perinatal infection and neurocognitive impairment persists even following antiretroviral treatment (ART)-mediated suppression of viremia. Compartmentalization of HIV-1 between plasma and CSF of ART-naïve, perinatally infected children suggests the presence of a CNS reservoir; however, similar studies have not yet been conducted with ART suppression. CSF viral escape where CSF and plasma virus concentrations are discordant has been reported in this population, but larger studies with well-defined virologic and immunologic parameters are needed. A better understanding of HIV-1 persistence in the CNS with perinatal infection is essential for improving long-term neurocognitive outcomes and for designing strategies to induce HIV-1 remission in this population.

Alternative Sample Types for HIV-1 Antiretroviral Drug Resistance Testing.

Monitoring human immunodeficiency virus type 1 (HIV-1) drug resistance is critical for assessing ART effectiveness and treatment outcomes for HIV-1-infected individuals, including children, worldwide. Traditionally, testing for HIV-1 drug resistance has primarily been performed on plasma samples, and with commercially available, clinically validated assays that are costly and difficult to access. While plasma is the preferred sample for HIV-1 drug resistance genotyping, plasma analysis requires sophisticated laboratory equipment, personnel, space, and stringent storage conditions for maintenance of sample integrity and transport. With the limitations in feasibility and affordability of providing these ideal conditions for plasma genotyping in resource-constrained settings, the field has gained substantial experience with the dried blood spot (DBS) technique as an alternative. Moreover, DBS analysis can be used to comprehensively monitor the spread of the epidemic with applications to more-sensitive and quantitative technologies to assess HIV-1 globally.

Inflammation and Immune Activation in Antiretroviral-Treated Human Immunodeficiency Virus Type 1-Infected African Infants and Rotavirus Vaccine Responses.

Biomarkers of inflammation and immune activation were correlated with rotavirus vaccine responses in 68 human immunodeficiency virus type 1 (HIV-1)­infected (and 116 HIV-exposed but uninfected (HEU) African infants receiving pentavalent rotavirus vaccine (RV5) in a clinical trial. Prevaccination, HIV-1+ infants had significantly higher concentrations of interferon γ (IFNγ), interleukin1ß, interleukin 2, interleukin 6, interleukin 10 (IL-10), and soluble CD14 compared with HEU infants. Postvaccination concentrations of neutralizing antibodies to RV5 were negatively correlated with prevaccination concentrations of IL-10 (RV5 surface proteins G1 and P1) and IFNγ (G1) in the HIV-1+ infants, whereas antirotavirus immunoglobulin A (IgA) levels were not. Heightened inflammation and immune activation in HIV-1+ infants did not alter IgA responses associated with protection from rotavirus disease.

Human Immunodeficiency Virus Type 1 DNA Decay Dynamics With Early, Long-term Virologic Control of Perinatal Infection.

BACKGROUND.: Early antiretroviral therapy (ART) limits proviral reservoirs, a goal for human immunodeficiency virus type 1 (HIV-1) remission strategies. Whether this is an immediate or long-term effect of virologic suppression (VS) in perinatal infection is unknown. METHODS.: We quantified HIV-1 DNA longitudinally for up to 14 years in peripheral blood mononuclear cells (PBMCs) among 61 perinatally HIV-1-infected youths in the Pediatric HIV/AIDS Cohort Study who achieved VS at different ages. Participants in group 1 (n = 13) were <1 year of age and in group 2 (n = 48) from 1 through 5 years of age at VS. Piecewise linear mixed-effects regression models assessed the effect of age at VS on HIV-1 DNA trajectories during VS. RESULTS.: In the first 2 years following VS, HIV-1 DNA levels decreased by -0.25 (95% confidence interval [CI], -.36 to -.13) log10 copies/million PBMCs per year and was faster with early VS by age 1 year compared with after age 1 (-0.50 and -0.15 log10 copies/million PBMCs per year, respectively). Between years 2 and 14 from VS, HIV-1 DNA decayed by -0.05 (95% CI, -.06 to -.03) log10 copies/million PBMCs per year and was no longer significantly different between groups. The estimated mean half-life of HIV-1 DNA from VS was 15.9 years and was shorter for group 1 compared to group 2 at 5.9 years and 18.8 years, respectively (P = .09). Adjusting for CD4 cell counts had no effect on decay estimates. CONCLUSIONS.: Early effective, long-term ART initiated from infancy leads to decay of HIV-1-infected cells to exceedingly low concentrations desired for HIV-1 remission strategies.

Soluble CD14: An Independent Biomarker for the Risk of Mother-to-Child Transmission of HIV in a Setting of Preexposure and Postexposure Antiretroviral Prophylaxis.

Elevated soluble CD14 (sCD14) concentrations, a marker of monocyte activation, predicts adverse outcomes in human immunodeficiency virus (HIV)-infected adults. To examine the association of sCD14 concentrations with the risk of mother-to-child transmission (MTCT) of HIV, we nested a case-control study (49 pairs of infants and their HIV-infected mothers) within the Six-Week Extended-Dose Nevirapine trial. Median peripartum maternal log2 sCD14 concentration was higher among transmitters (defined as pairs in which maternally transmitted HIV infection occurred by 12 months of age) than nontransmitters (20.29 pg/mL vs 19.41 pg/mL; P = .005). There was an increased odds of MTCT for every log2 increase in maternal sCD14 concentration, after adjustment for maternal HIV load, CD4 count and cART exposure (adjusted odds ratio, 3.51; 95% confidence interval, 1.21-10.21). Maternal monocyte activation may adversely influence the risk of MTCT of HIV.

Absence of detectable HIV-1 viremia after treatment cessation in an infant.

An infant born to a woman with human immunodeficiency virus type 1 (HIV-1) infection began receiving antiretroviral therapy (ART) 30 hours after birth owing to high-risk exposure. ART was continued when detection of HIV-1 DNA and RNA on repeat testing met the standard diagnostic criteria for infection. After therapy was discontinued (when the child was 18 months of age), levels of plasma HIV-1 RNA, proviral DNA in peripheral-blood mononuclear cells, and HIV-1 antibodies, as assessed by means of clinical assays, remained undetectable in the child through 30 months of age. This case suggests that very early ART in infants may alter the establishment and long-term persistence of HIV-1 infection.

Advances and hope for perinatal HIV remission and cure in children and adolescents.

PURPOSE OF REVIEW: The known timing of HIV infection in perinatal transmission, combined with the capacity for early antiretroviral therapy (ART) initiation and immune reconstitution, can provide unique insights into HIV persistence. The scientific basis for a pediatric-specific research agenda aimed at HIV remission and cure is discussed. RECENT FINDINGS: Accumulating evidence supports a favorable biomarker profile for immunotherapeutic interventions in early treated, perinatally infected individuals. HIV DNA concentrations in infected cells of early treated infants decrease over the first few years of life and, after more than 10 years of ART, the overwhelming majority of noninduced proviral genomes are replication-deficient. With early ART initiation, approximately half of perinatally infected individuals become seronegative. Studies of untreated infants and vaccine trials indicate that infected infants can generate HIV-specific humoral responses. Taken together, this evidence suggests that early treatment results in low levels of replication-competent provirus, an absence of HIV-specific immunity, and the capacity to generate immune responses to potential immunotherapeutic interventions. SUMMARY: Perinatally HIV-infected individuals require lifelong ART because of the prompt establishment of viral latency in long-lived resting memory CD4 T cells that rekindle viremia upon treatment cessation. However, intense research efforts are ongoing to perturb HIV latency toward reservoir clearance for virologic remission and cure in which perinatally infected individuals can discontinue ART.

Cell-Associated HIV-1 DNA and RNA Decay Dynamics During Early Combination Antiretroviral Therapy in HIV-1-Infected Infants.

BACKGROUND: The decay of human immunodeficiency virus type 1 (HIV-1)-infected cells during early combination antiretroviral therapy (cART) in infected infants is not defined. METHODS: HIV-1 DNA, including 2-long terminal repeat (2-LTR) circles, and multiply spliced (ms-) and unspliced (us-) HIV-1 RNA concentrations were measured at 0, 24, 48, and 96 weeks of cART in infants from the IMPAACT P1030 trial receiving lopinavir-ritonavir-based cART. The ratio of HIV-1 DNA concentrations to replication-competent genomes was also estimated. Linear mixed effects models with random intercept and linear splines were used to estimate patient-specific decay kinetics of HIV-1 DNA. RESULTS: The median HIV-1 DNA concentration before cART at a median age of 2 months was 3.2 log10 copies per million PBMC. With cART, the average estimated patient-specific change in HIV-1 DNA concentrations was -0.040 log10/week (95% confidence interval [CI], -.05, -.03) between 0 and 24 weeks and -0.017 log10/week between 24 and 48 weeks (95% CI, -.024, -.01). 2-LTR circles decreased with cART but remained detectable through 96 weeks. Pre-cART HIV-1 DNA concentration was correlated with time to undetectable plasma viral load and post-cART HIV-1 DNA at 96 weeks; although HIV-1 DNA concentrations exceeded replication-competent HIV-1 genomes by 148-fold. Almost all infants had ms- and usRNA detected pre-cART, with 75% having usRNA through 96 weeks of cART. CONCLUSIONS: By 2 months of age, a large pool of HIV-1-infected cells is established in perinatal infection, which influences time to undetectable viral load and reservoir size. This has implications for informing novel approaches aimed at early restriction of HIV-1 reservoirs to enable virologic remission and cure.