Early initiation of antiretroviral therapy (ART) in vertically HIV-infected children limits the size of the virus reservoir, but whether the time of treatment initiation (TI) can durably impact host immune responses associated with HIV infection is still unknown. This study was conducted in PBMC of 20 HIV-infected virally suppressed children on ART (mean age 9.4 y), classified as early treated (ET; age at ART initiation ≤0.5 y, n = 14) or late treated (LT; age at ART initiation 1–10 y, n = 6). Frequencies and functions of Ag-specific CD4 (CD40L⁺) and CD8 (CD69⁺) T cells were evaluated by intracellular IL-2, IFN-γ, and TNF-α production with IL-21 in CD4 or CD107a, granzyme B and perforin in CD8 T cells following stimulation with HIV gp140 protein (ENV) or GAG peptides by multiparameter flow cytometry. ET showed a higher proportion of cytokine-producing ENV- and GAG-specific CD4 and CD8 T cells compared with LT. In particular, ET were enriched in polyfunctional T cells. RNA sequencing analysis showed upregulation of immune activation pathways in LT compared with ET. Our results suggest that timing of TI in HIV-infected children has a long-term and measurable impact on the quality of the HIV-specific T cell immune responses and transcriptional profiles of PBMC, reinforcing the importance of early TI. Key Points HIV-specific T cell responses persist despite long-term viral suppression. Timing of ART initiation impacts the quality of the HIV-specific T cell responses. Baseline PBMC transcriptome is different in HIV-infected children treated early.

The persistence of HIV-1-infected cells during antiretroviral therapy is well documented but may be modulated by early initiation of antiretroviral therapy in infants. Here, we longitudinally analyzed the proviral landscape in nine infants with vertical HIV-1 infection from Mozambique over a median period of 24 months, using single-genome, near full-length, next-generation proviral sequencing. We observed a rapid decline in the frequency of intact proviruses, leading to a disproportional under-representation of intact HIV-1 sequences within the total number of HIV-1 DNA sequences after 12–24 months of therapy. In addition, proviral integration site profiling in one infant demonstrated clonal expansion of infected cells harboring intact proviruses and indicated that viral rebound was associated with an integration site profile dominated by intact proviruses integrated into genic and accessible chromatin locations. Together, these results permit rare insight into the evolution of the HIV-1 reservoir in infants infected with HIV-1 and suggest that the rapid decline of intact proviruses, relative to defective proviruses, may be attributed to a higher vulnerability of genome-intact proviruses to antiviral immunity. Technologies to analyze combinations of intact proviral sequences and corresponding integration sites permit a high-resolution analysis of HIV-1 reservoir cells after early antiretroviral treatment initiation in infants.

Early initiation of antiretroviral therapy and adherence to achieve viral load suppression (VLS) are crucial for reducing morbidity and mortality of perinatally HIV-infected infants. In this descriptive cohort study of 39 HIV perinatally infected infants, who started treatment at one month of life in Mozambique, we aimed to describe the viral response over 2 years of follow up. VLS ≤ 400 copies/mL, sustained VLS and viral rebound were described using a Kaplan–Meier estimator. Antiretroviral drug transmitted resistance was assessed for a sub-group of non-VLS infants. In total, 61% of infants reached VLS, and 50% had a rebound. Cumulative probability of VLS was 36%, 51%, and 69% at 6, 12 and 24 months of treatment, respectively. The median duration of VLS was 7.4 months (IQR 12.6) and the cumulative probability of rebound at 6 months was 30%. Two infants had resistance biomarkers to drugs included in their treatment regimen. Our findings point to a low rate of VLS and high rate of viral rebound. More frequent viral response monitoring is advisable to identify infants with rebound and offer timely adherence support. It is urgent to tailor the psychosocial support model of care to this specific age group and offer differentiated service delivery to mother–baby pairs.

Psychosocial support (PSS) to caregivers of HIV-infected infants on antiretroviral treatment (ART) is crucial to ensure ART adherence and sustained long-term viral suppression in children. A specific approach including tools to monitor and understand adherence behavior and risk factors that prevent optimal treatment compliance are urgently needed. This qualitative exploratory study, conducted in southern Mozambique, monitored the infants’ viral response trajectories during 18 months follow-up, as a measure of adherence, reviewed the caregiver’s PSS session notes and the answers to a study questionnaire, to analyze whether the standard PSS checklist applied to infants’ caregivers can identify barriers influencing their adherence. Only 9 of 31 infants had sustained virologic response. Reported factors affecting adherence were: difficulties in drugs administration, shared responsibility to administer treatment; disclosure of child’s HIV status to family members but lack of engagement; mother’s ART interruption and poor viral response. In conclusion, we found that the standard PSS approach alone, applied to caregivers, was lacking focus on many relevant matters that were identified by the study questionnaire. A comprehensive patient-centered PSS package of care, including an adherence risk factor monitoring tool, tailored to caregivers and their children must be developed.

Complete follow-up of human immunodeficiency virus (HIV)-exposed infants (HEI) is crucial for a successful prevention of mother-to-child HIV transmission. This study analyzed the HEI follow-up and factors associated with loss to follow-up (LTFU) in southern Mozambique. This retrospective cohort study used the data of HEI enrolled between June 2017 and June 2018, followed-up for 18 months. The outcomes were the proportion of infants with completed follow-up and a definitive diagnosis, and the presence of clinical events. Kaplan–Meier survival analysis was used to calculate the cumulative probability of LTFU and of clinical events. Factors associated with LTFU and clinical events were analyzed using Cox regression to calculate the hazard ratio (HR) and adjusted HR (AHR), with a 95% confidence interval (CI) and a significance cutoff of p2 months at entry (AHR, 1.58; 95% CI, 1.12–2.23), non-exclusive breastfeeding (AHR, 1.44; 95% CI, 1.01–2.06), poor cotrimoxazole adherence (AHR, 3.42; 95% CI, 1.59–7.35), and clinical events (AHR, 0.51; 95% CI, 0.34–0.77). Factors associated with clinical events were: malnutrition (AHR, 10.06; 95% CI, 5.92–17.09), non-exclusive breastfeeding (AHR, 1.98; 95% CI, 1.34–2.93), no nevirapine prophylaxis (AHR, 1.67; 95% CI, 1.18–2.36), and poor cotrimoxazole adherence (AHR, 2.62; 95% CI, 1.10–6.22). The high rate of HEI LTFU, associated with delayed linkage to postnatal care, poor prophylaxis adherence, non-exclusive breastfeeding, indicates the need to design a differentiated service delivery model that is tailored to the mothers’ and infants’ specific needs.

Background: The World Health Organization (WHO) risk assessment algorithm for vertical transmission of HIV (VT) assumes the availability of maternal viral load (VL) result at delivery and early viral control 4 weeks after initiating antiretroviral treatment (ART). However, in many low-and-middle-income countries, VL is often unavailable and mothers’ ART adherence may be suboptimal. We evaluate the inclusion of the mothers’ self-reported adherence into the established WHO-algorithm to identify infants eligible for enhanced post-natal prophylaxis when mothers’ VL result is not available at delivery. Methods: We used data from infants with perinatal HIV infection and their mothers enrolled from May-2018 to May-2020 in Mozambique, South Africa, and Mali. We retrospectively compared the performance of the WHO-algorithm with a modified algorithm which included mothers’ adherence as an additional factor. Infants were considered at high risk if born from mothers without a VL result in the 4 weeks before delivery and with adherence <90%. Results: At delivery, 143/184(78%) women with HIV knew their status and were on ART. Only 17(12%) obtained a VL result within 4 weeks before delivery, and 13/17(76%) of them had VL ≥1000 copies/ml. From 126 women on ART without a recent VL result, 99(79%) had been on ART for over 4 weeks. 45/99(45%) women reported suboptimal (< 90%) adherence. A total of 81/184(44%) infants were classified as high risk of VT as per the WHO-algorithm. The modified algorithm including self-adherence disclosure identified 126/184(68%) high risk infants. Conclusions: In the absence of a VL result, mothers’ self-reported adherence at delivery increases the number of identified infants eligible to receive enhanced post-natal prophylaxis.