Efficacy of the ChAdOx1 nCoV-19 Covid-19 Vaccine against the B.1.351 Variant.

BACKGROUND: Assessment of the safety and efficacy of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in different populations is essential, as is investigation of the efficacy of the vaccines against emerging SARS-CoV-2 variants of concern, including the B.1.351 (501Y.V2) variant first identified in South Africa. METHODS: We conducted a multicenter, double-blind, randomized, controlled trial to assess the safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) in people not infected with the human immunodeficiency virus (HIV) in South Africa. Participants 18 to less than 65 years of age were assigned in a 1:1 ratio to receive two doses of vaccine containing 5×1010 viral particles or placebo (0.9% sodium chloride solution) 21 to 35 days apart. Serum samples obtained from 25 participants after the second dose were tested by pseudovirus and live-virus neutralization assays against the original D614G virus and the B.1.351 variant. The primary end points were safety and efficacy of the vaccine against laboratory-confirmed symptomatic coronavirus 2019 illness (Covid-19) more than 14 days after the second dose. RESULTS: Between June 24 and November 9, 2020, we enrolled 2026 HIV-negative adults (median age, 30 years); 1010 and 1011 participants received at least one dose of placebo or vaccine, respectively. Both the pseudovirus and the live-virus neutralization assays showed greater resistance to the B.1.351 variant in serum samples obtained from vaccine recipients than in samples from placebo recipients. In the primary end-point analysis, mild-to-moderate Covid-19 developed in 23 of 717 placebo recipients (3.2%) and in 19 of 750 vaccine recipients (2.5%), for an efficacy of 21.9% (95% confidence interval [CI], -49.9 to 59.8). Among the 42 participants with Covid-19, 39 cases (95.1% of 41 with sequencing data) were caused by the B.1.351 variant; vaccine efficacy against this variant, analyzed as a secondary end point, was 10.4% (95% CI, -76.8 to 54.8). The incidence of serious adverse events was balanced between the vaccine and placebo groups. CONCLUSIONS: A two-dose regimen of the ChAdOx1 nCoV-19 vaccine did not show protection against mild-to-moderate Covid-19 due to the B.1.351 variant. (Funded by the Bill and Melinda Gates Foundation and others; ClinicalTrials.gov number, NCT04444674; Pan African Clinical Trials Registry number, PACTR202006922165132).

Growth Trajectories Over the First Year of Life Among Early-Treated Infants with Human Immunodeficiency Virus and Infants Who are Human Immunodeficiency Virus-Exposed Uninfected.

OBJECTIVE: To investigate the role of early antiretroviral therapy (ART) on growth trajectories of infants with human immunodeficiency virus (IHIV) in the first year of life. STUDY DESIGN: As part of a clinical trial of early ART in Johannesburg, South Africa (2015-2018), 116 IHIV diagnosed within 48 hours of birth were started on ART as soon as possible, and 80 uninfected infants born to mothers living with HIV (IHEU) were enrolled. Both groups were followed prospectively from birth through 48 weeks and growth parameters collected. The groups were compared and risk factors for poor growth investigated, in the full cohort and among IHIV separately. RESULTS: IHIV had lower mean weight-for-age Z-scores (WAZ) than IHEU at 4 and 8 weeks (-1.17 [SE:0.14] vs -0.72 [0.14], P = .035 and -1.23 [0.15] vs -0.67 [0.14], P = .012). Although there was some closing of the gap over time, means remained lower in IHIV through 48 weeks. In length-for-age Z-scores (LAZ), differences widened over time and IHIV had lower Z-scores by 48 weeks (-1.41 [0.15] vs -0.80 [0.18], P = .011). Deficits in WAZ and LAZ in IHIV vs IHEU were most marked among girls. IHIV with pre-ART viral load ≥1000 copies/ml had significantly lower weight-for-length and mid-upper arm circumference Z-scores across all time points through 48 weeks. CONCLUSIONS: IHIV on early ART had deficits in WAZ over the first 8 weeks of life and lower LAZ at 48 weeks than IHEU. Among IHIV, higher pre-ART viral load was associated with worse anthropometric indicators through 48 weeks.

Disclosure to South African children about their own HIV status over time.

Disclosure to children living with HIV (CLHIV) about their own status is associated with positive outcomes such as treatment adherence, but prior cross-sectional studies in sub-Saharan Africa report disclosure rates of <50%. This study aims to assess pediatric disclosure over time. 548 CLHIV were followed from 2/2013-4/2018 in Johannesburg, South Africa. Cumulative incidence of disclosure was calculated with Kaplan-Meier analysis, and disclosure characteristics assessed with a Cox model. By end of follow-up, cumulative disclosure was 70.3% (95% confidence interval: 60.0-79.9). Median age at disclosure was 9 years (range: 3-13). Baseline predictors of disclosure included older child age and the child having a history of going hungry. Prior to disclosure, 98.0% of caregivers who disclosed had conversed with their child about their illness or an HIV-related topic, or their child had asked about HIV, versus 88.6% of caregivers who never disclosed. While many children did not receive disclosure during this relatively large, longitudinal study of South African CLHIV, caregivers who had not yet disclosed may have been preparing to do so by discussing their child's health or HIV generally with their child. This highlights the need for clinicians to consistently support caregivers throughout the incremental disclosure process.

Predictors of Cell-Associated Human Immunodeficiency Virus (HIV)-1 DNA Over 1 Year in Very Early Treated Infants.

BACKGROUND: Younger age of antiretroviral therapy (ART) initiation is associated with smaller viral reservoirs in perinatally acquired HIV-1 infection, but there is wide variability among early-treated infants. Predictors of this variability are not fully described. METHODS: Sixty-three neonates diagnosed with HIV-1 <48 hours after birth in Johannesburg, South Africa, were started on ART as soon as possible. Fifty-nine (94%) infants received nevirapine prophylaxis from birth until ART start. Viably preserved peripheral blood mononuclear cells (PBMCs) collected at regular intervals to 48 weeks, and from mothers at enrollment, were tested using integrase-targeted, semi-nested, real-time quantitative hydrolysis probe (TaqMan) PCR assays to quantify total HIV-1 subtype C viral DNA (vDNA). Predictors were investigated using generalized estimating equation regression. RESULTS: Thirty-one (49.2%) infants initiated ART <48 hours, 24 (38.1%) <14 days, and 8 (12.7%) >14 days of birth. Three-quarters were infected despite maternal antenatal ART (however, only 9.5% of women had undetectable viral load closest to delivery) and 86% were breastfed. Higher infant CD4+ T-cell percentage and viral load <100 000 copies/mL pre-ART were associated with lower vDNA in the first 48 weeks after ART start. No antenatal maternal ART and breastfeeding were also associated with lower vDNA. Older age at ART initiation had a discernible negative impact when initiated >14 days. CONCLUSIONS: Among very early treated infants, higher CD4+ T-cell percentage and viral load <100 000 copies/mL pre-ART, infection occurring in the absence of maternal antenatal ART, and breastfeeding were associated with lower levels of HIV-1 DNA in the first 48 weeks of treatment. Clinical Trials Registration. clinicaltrials.gov (NCT02431975).

Switch to Efavirenz Attenuates Lipoatrophy in Girls With Perinatal HIV.

OBJECTIVES: Children with HIV (CHIV) have lifetime exposure to antiretrovirals (ART); therefore, optimizing their regimens to have the least impact on fat redistribution is a priority. METHODS: This is a cross-sectional study of 219 perinatally infected CHIV and 219 HIV-uninfected controls from similar socioeconomic backgrounds in Johannesburg, South Africa. We compared total body and regional fat distribution in CHIV on suppressive ART regimens with controls and, among CHIV, between ritonavir-boosted lopinavir (LPV/r)-based and efavirenz (EFV)-based regimens. RESULTS: The mean age of the 219 uninfected children (45% girls) and the 219 CHIV (48% girls) was 7.0 and 6.4 years, respectively. CHIV had lower adjusted total body fat (P = 0.005) and lower percentage fat at the trunk (P = 0.020), arms (P = 0.001), and legs (P < 0.001) than uninfected children. CHIV on LPV/r had similar body composition as those on EFV, except for arm fat mass (P = 0.030). When stratified by sex, girls with HIV on LPV/r had lower adjusted total (P = 0.007), trunk (P = 0.002), arms (P = 0.008), legs (P = 0.048) fat mass; trunk-to-total body fat (P = 0.044); and higher legs-to-total body fat (P = 0.011) than those on EFV. CONCLUSIONS: South African CHIV receiving ART had lower global and partial fat mass and percentage fat than healthy controls. In girls with HIV with sustained virologic suppression on ART, switching from LPV/r to EFV could attenuate fat mass loss, indicating that EFV-based regimen may be a better option in this group of individuals.

Educational delays among children living with perinatally-acquired HIV in Johannesburg, South Africa.

Little is known about how growing up with HIV impacts educational outcomes in sub-Saharan African children. We evaluated if South African children living with HIV (CLWH) were in the appropriate school grade-for-age compared to uninfected control children. We observed higher rates of not being in the correct grade-for-age in CLWH compared with controls (OR 3.32, 95% CI: 2.07-5.34), adjusted for study site, sex, whether the child's biological father was alive, and caregiver education. Initiation of ART before 6 months of age reduced but did not eliminate this association. Whether these associations are due to biological factors or other social and environmental determinants, and how best to support CLWH to achieve educational goals, warrants further investigation.

Bone Quality Measured Using Calcaneal Quantitative Ultrasonography Is Reduced Among Children with HIV in Johannesburg, South Africa.

We evaluated bone quality among South African children with HIV over a 2-year period by quantitative ultrasound (QUS). Children with HIV have persistently lower bone quality compared with controls reflecting increased porosity, reduced strength, and possibly an increased short- and long-term risk of fracture.

Switching to Efavirenz Versus Remaining on Ritonavir-boosted Lopinavir in Human Immunodeficiency Virus-infected Children Exposed to Nevirapine: Long-term Outcomes of a Randomized Trial.

BACKGROUND: We previously demonstrated the noninferiority of switching to efavirenz (EFV) versus remaining on ritonavir-boosted lopinavir (LPV/r) for virologic control in children infected with human immunodeficiency virus (HIV) and exposed to nevirapine (NVP) for prevention of mother-to-child transmission. Here we assess outcomes up to 4 years post-randomization. METHODS: From 2010-2013, 298 NVP-exposed HIV-infected children ≥3 years of age were randomized to switch to EFV or remain on LPV/r in Johannesburg, South Africa (Clinicaltrials.gov NCT01146873). After trial completion, participants were invited to enroll into observational follow-up. We compared HIV RNA levels, CD4 counts and percentages, lipids, and growth across groups through four years post-randomization. RESULTS: HIV RNA levels 51-1000 copies/mL were less frequently observed in the EFV group than the LPV/r group (odds ratio [OR] 0.67, 95% confidence interval [CI]: 0.51-0.88, P = .004), as was HIV RNA >1000 copies/mL (OR 0.52 95% CI: 0.28-0.98, P = .04). The probability of confirmed HIV RNA >1000 copies/mL by 48 months was 0.07 and 0.12 in the EFV and LPV/r groups, respectively (P = .21). Children randomized to EFV had a reduced risk of elevated total cholesterol (OR 0.45 95% CI: 0.27-0.75, P = .002) and a reduced risk of abnormal triglycerides (OR 0.42, 95% CI 0.29-0.62, P < .001). CONCLUSIONS: Our results indicate that the benefits of switching virologically suppressed NVP-exposed HIV-infected children ≥3 years of age from LPV/r to EFV are sustained long-term. This approach has several advantages, including improved palatability, reduced metabolic toxicity, simplified cotreatment for tuberculosis, and preservation of second line options. CLINICAL TRIALS REGISTRATION: NCT01146873.

Extent of disclosure: what perinatally HIV-infected children have been told about their own HIV status.

How and when to disclose a positive HIV diagnosis to an infected child is a complex challenge for caregivers and healthcare workers. With the introduction of antiretroviral therapy, pediatric HIV infection has transitioned from a fatal disease to a lifelong chronic illness, thus increasing the need to address the disclosure process. As HIV-infected children mature, begin to take part in management of their own health care, and potentially initiate HIV-risk behaviors, understanding the nature of their infection becomes essential. Guidelines recommend developmentally appropriate incremental disclosure, and emphasize full disclosure to school-age children. However, studies from Sub-Saharan Africa report that disclosure to HIV-infected children is often delayed. Between 2013 and 2014, 553 perinatally HIV-infected children aged 4-9 years were enrolled into a cohort study in Johannesburg, South Africa. We assessed the extent of disclosure among these children and evaluated characteristics associated with disclosure. No children aged 4 years had been told their status, while 4% of those aged 5 years, and 8%, 13%, 16%, and 15% of those aged 6, 7, 8, and 9 years, respectively, had been told their status. Age was the strongest predictor of full disclosure (odds ratio 1.6 per year, p = .001). An adult living in the household who was unaware of the child's status was associated with a reduced probability of disclosure, and knowing that someone at the child's school was aware of child's status was associated with an increased probability of disclosure. Among caregivers who had not disclosed, 42% reported ever discussing illness in general with the child, and 17% reported ongoing conversations about illness or HIV. In conclusion, a small minority of school-age children had received full disclosure. Caregivers and healthcare workers require additional support to address disclosure. A broader public health strategy integrating the disclosure process into pediatric HIV treatment programs is recommended.

Dietary Inadequacies in HIV-infected and Uninfected School-aged Children in Johannesburg, South Africa.

OBJECTIVES: The World Health Organization recommends that human immunodeficiency virus (HIV)-infected children increase energy intake and maintain a balanced macronutrient distribution for optimal growth and nutrition. Few studies have evaluated dietary intake of HIV-infected children in resource-limited settings. METHODS: We conducted a cross-sectional analysis of the dietary intake of 220 perinatally HIV-infected children and 220 HIV-uninfected controls ages 5 to 9 years in Johannesburg, South Africa. A standardized 24-hour recall questionnaire and software developed specifically for the South African population were used to estimate intake of energy, macronutrients, and micronutrients. Intake was categorized based on recommendations by the World Health Organization and Acceptable Macronutrient Distribution Ranges established by the IOM. RESULTS: The overall mean age was 6.7 years and 51.8% were boys. Total energy intake was higher in HIV-infected than HIV-uninfected children (1341 vs 1196 kcal/day, P = 0.002), but proportions below the recommended energy requirement were similar in the 2 groups (82.5% vs 85.2%, P = 0.45). Overall, 51.8% of the macronutrient energy intake was from carbohydrates, 13.2% from protein, and 30.8% from fat. The HIV-infected group had a higher percentage of their energy intake from carbohydrates and lower percentage from protein compared with the HIV-uninfected group. Intakes of folate, vitamin A, vitamin D, calcium, iodine, and selenium were suboptimal for both groups. CONCLUSIONS: Our findings suggest that the typical diet of HIV-infected children and uninfected children in Johannesburg, South Africa, does not meet energy or micronutrient requirements. There appear to be opportunities for interventions to improve dietary intake for both groups.

Decreased Vigorous Physical Activity in School-Aged Children with Human Immunodeficiency Virus in Johannesburg, South Africa.

OBJECTIVE: To describe physical activity in South African children with and without HIV. STUDY DESIGN: Study measurements were obtained in 218 children with perinatal HIV and 180 children without HIV aged 5-9 years in a study conducted in Johannesburg, South Africa. Weight-for-age z-score, height-for-age z-score, frequency and duration of moderate and vigorous physical activity, and sedentary behaviors were obtained. These measurements were compared between children with and without HIV. RESULTS: Weight-for-age z-score and height-for-age z-score were significantly lower for children with HIV compared with those without HIV. Among children who attended school, fewer children with HIV than children without HIV participated in physical education (41% vs 64%; P = .0003) and organized after-school sports (38% vs 64%; P < .001). The proportion of children in both groups meeting World Health Organization recommendations for physical activity was similar (84% overall); however, girls with HIV spent less time in vigorous physical activity than girls without HIV (420 vs 780 minutes/week; P = .001). This difference remained significant even when girls with a medical condition with the potential to limit physical activity were excluded, and after adjusting for age. Time spent in sedentary behaviors did not differ significantly between the two groups. CONCLUSION: Although children with HIV with well-controlled disease after initiating antiretroviral therapy early in life achieve high levels of physical activity, vigorous physical activity is lower in girls with HIV than in healthy controls. This finding may reflect lower participation in school-based physical education and organized after-school physical activity.

Case report: Severe central nervous system manifestations associated with aberrant efavirenz metabolism in children: the role of CYP2B6 genetic variation.

BACKGROUND: Efavirenz, widely used as part of antiretroviral drug regimens in the treatment of paediatric human immunodeficiency virus infection, has central nervous system side effects. We describe four children presenting with serious, persistent central nervous system adverse events who were found to have elevated plasma efavirenz concentrations as a result of carrying CYP2B6 single nucleotide polymorphisms, known to play a role in the metabolism of EFV. None of the children had a CYP2B6 wildtype haplotype. We believe this is the first case of cerebellar dysfunction associated with efavirenz use to be described in children. CASE PRESENTATION: Four black African children, between the ages of 4 and 8 years presenting between 1 and 20 months post-efavirenz initiation, are described. Cerebellar dysfunction, generalised seizures and absence seizures were the range of presenting abnormalities. Plasma efavirenz levels ranged from 20-60 mg/L, 5-15 times the upper limit of the suggested reference range. All abnormal central nervous system manifestations abated after efavirenz discontinuation. CONCLUSION: Efavirenz toxicity should always be considered in human immunodeficiency virus-infected children with unexplained central nervous system abnormalities. Our findings further our understanding of the impact of genetic variants on antiretroviral pharmacokinetics in children across various ethnic groups. Screening for potential EFV-toxicity based on the CYP2B6 c.516 SNP alone, may not be adequate.

Efavirenz-Based Antiretroviral Therapy Among Nevirapine-Exposed HIV-Infected Children in South Africa: A Randomized Clinical Trial.

IMPORTANCE: Advantages of using efavirenz as part of treatment for children infected with human immunodeficiency virus (HIV) include once-daily dosing, simplification of co-treatment for tuberculosis, preservation of ritonavir-boosted lopinavir for second-line treatment, and harmonization of adult and pediatric treatment regimens. However, there have been concerns about possible reduced viral efficacy of efavirenz in children exposed to nevirapine for prevention of mother-to-child transmission. OBJECTIVE: To evaluate whether nevirapine-exposed children achieving initial viral suppression with ritonavir-boosted lopinavir-based therapy can transition to efavirenz-based therapy without risk of viral failure. DESIGN, SETTING, AND PARTICIPANTS: Randomized, open-label noninferiority trial conducted at Rahima Moosa Mother and Child Hospital, Johannesburg, South Africa, from June 2010 to December 2013, enrolling 300 HIV-infected children exposed to nevirapine for prevention of mother-to-child transmission who were aged 3 years or older and had plasma HIV RNA of less than 50 copies/mL during ritonavir-boosted lopinavir-based therapy; 298 were randomized and 292 (98%) were followed up to 48 weeks after randomization. INTERVENTIONS: Participants were randomly assigned to switch to efavirenz-based therapy (n = 150) or continue ritonavir-boosted lopinavir-based therapy (n = 148). MAIN OUTCOMES AND MEASURES: Risk difference between groups in (1) viral rebound (ie, ≥1 HIV RNA measurement of >50 copies/mL) and (2) viral failure (ie, confirmed HIV RNA >1000 copies/mL) with a noninferiority bound of -0.10. Immunologic and clinical responses were secondary end points. RESULTS: The Kaplan-Meier probability of viral rebound by 48 weeks was 0.176 (n = 26) in the efavirenz group and 0.284 (n = 42) in the ritonavir-boosted lopinavir group. Probabilities of viral failure were 0.027 (n = 4) in the efavirenz group and 0.020 (n = 3) in the ritonavir-boosted lopinavir group. The risk difference for viral rebound was 0.107 (1-sided 95% CI, 0.028 to ∞) and for viral failure was -0.007 (1-sided 95% CI, -0.036 to ∞). We rejected the null hypothesis that efavirenz is inferior to ritonavir-boosted lopinavir (P < .001) for both end points. By 48 weeks, CD4 cell percentage was 2.88% (95% CI, 1.26%-4.49%) higher in the efavirenz group than in the ritonavir-boosted lopinavir group. CONCLUSIONS AND RELEVANCE: Among HIV-infected children exposed to nevirapine for prevention of mother-to-child transmission and with initial viral suppression with ritonavir-boosted lopinavir-based therapy, switching to efavirenz-based therapy compared with continuing ritonavir-boosted lopinavir-based therapy did not result in significantly higher rates of viral rebound or viral failure. This therapeutic approach may offer advantages in children such as these. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01146873.

Safety and immunogenicity of booster vaccination and fractional dosing with Ad26.COV2.S or BNT162b2 in Ad26.COV2.S-vaccinated participants.

We report the safety and immunogenicity of fractional and full dose Ad26.COV2.S and BNT162b2 in an open label phase 2 trial of participants previously vaccinated with a single dose of Ad26.COV2.S, with 91.4% showing evidence of previous SARS-CoV-2 infection. A total of 286 adults (with or without HIV) were enrolled >4 months after an Ad26.COV2.S prime and randomized 1:1:1:1 to receive either a full or half-dose booster of Ad26.COV2.S or BNT162b2 vaccine. B cell responses (binding, neutralization and antibody dependent cellular cytotoxicity-ADCC), and spike-specific T-cell responses were evaluated at baseline, 2, 12 and 24 weeks post-boost. Antibody and T-cell immunity targeting the Ad26 vector was also evaluated. No vaccine-associated serious adverse events were recorded. The full- and half-dose BNT162b2 boosted anti-SARS-CoV-2 binding antibody levels (3.9- and 4.5-fold, respectively) and neutralizing antibody levels (4.4- and 10-fold). Binding and neutralizing antibodies following half-dose Ad26.COV2.S were not significantly boosted. Full-dose Ad26.COV2.S did not boost binding antibodies but slightly enhanced neutralizing antibodies (2.1-fold). ADCC was marginally increased only after a full-dose BNT162b2. T-cell responses followed a similar pattern to neutralizing antibodies. Six months post-boost, antibody and T-cell responses had waned to baseline levels. While we detected strong anti-vector immunity, there was no correlation between anti-vector immunity in Ad26.COV2.S recipients and spike-specific neutralizing antibody or T-cell responses post-Ad26.COV2.S boosting. Overall, in the context of hybrid immunity, boosting with heterologous full- or half-dose BNT162b2 mRNA vaccine demonstrated superior immunogenicity 2 weeks post-vaccination compared to homologous Ad26.COV2.S, though rapid waning occurred by 12 weeks post-boost. Trial Registration: The study has been registered to the South African National Clinical Trial Registry (SANCTR): DOH-27-012022-7841. The approval letter from SANCTR has been provided in the up-loaded documents.

Initiation of antiretroviral therapy before 6 months of age is associated with faster growth recovery in South African children perinatally infected with human immunodeficiency virus.

OBJECTIVE: To describe the effects of age at antiretroviral therapy (ART) initiation on growth outcomes among children infected with HIV followed for 48 months after treatment initiation. STUDY DESIGN: This secondary analysis describes anthropometric changes in children infected with HIV in Johannesburg, South Africa who initiated ritonavir-boosted lopinavir-based ART before 24 months of age and were randomized to continue ritonavir-boosted lopinavir or to receive nevirapine after achieving and maintaining virologic suppression. Weight, height, and head circumference were measured at visits over 48 months post-ART initiation. Growth patterns including weight-for-age z-scores (WAZs), height-for-age z-scores, body mass index-for-age z-scores, and head circumference for age z-score were compared between children initiating ART<6 months, 6-12 months, and 12-24 months of age. RESULTS: A total of 195 children (mean±SD age 10.7±5.9 months), including 54 (27.7%)<6 months, 69 (35.4%) 6-12 months, and 72 (36.9%) 12-24 months of age at ART initiation, were evaluated. In the first 12 months on treatment, children<6 months of age at ART initiation experienced more rapid improvement in WAZ (1.98 vs 1.44, P=.084) and head circumference for age z-score (1.24 vs 0.45, P=.004) than children who initiated ART between 12-24 months of age. By 48 months on ART, growth outcomes were similar, regardless of age at ART initiation. WAZ approached population norms by 12 months on ART. Although improving, height-for-age z-scores remained on average 1.0 z-score below population norms at 48 months of therapy. CONCLUSIONS: Initiation of ART before 6 months of age results in more rapid growth recovery in children infected with HIV. These data provide further evidence for the importance of prompt diagnosis and early initiation of ART for infants infected with HIV.

Microbiota in the oral cavity of school-age children with HIV who started antiretroviral therapy at young ages in South Africa.

BACKGROUND: Infancy is an important developmental period when the microbiome is shaped. We hypothesized that earlier antiretroviral therapy (ART) initiation would attenuate HIV effects on microbiota in the mouth. METHODS: Oral swabs were collected from 477 children with HIV (CWH) and 123 children without (controls) at two sites in Johannesburg, South Africa. CWH had started ART less than 3 years of age; 63% less than 6 months of age. Most were well controlled on ART at median age 11 years when the swab was collected. Controls were age-matched and recruited from the same communities. Sequencing of V4 amplicon of 16S rRNA was done. Differences in microbial diversity and relative abundances of taxa were compared between the groups. RESULTS: CWH had lower alpha diversity than controls. Genus-level abundances of Granulicatella, Streptococcus, and Gemella were greater and Neisseria and Haemophilus less abundant among CWH than controls. Associations were stronger among boys. Associations were not attenuated with earlier ART initiation. Shifts in genus-level taxa abundances in CWH relative to controls were most marked in children on lopinavir/ritonavir regimens, with fewer shifts seen if on efavirenz ART regimens. CONCLUSION: A distinct profile of less diverse oral bacterial taxa was observed in school-aged CWH on ART compared with uninfected controls suggesting modulation of microbiota in the mouth by HIV and/or its treatments. Earlier ART initiation was not associated with microbiota profile. Proximal factors, including current ART regimen, were associated with contemporaneous profile of oral microbiota and may have masked associations with distal factors such as age at ART initiation.

Safety surveillance for PrEP in pregnant and breastfeeding women.

The risk of HIV acquisition is higher during pregnancy and postpartum than other times. Newly acquired maternal HIV infection associated with high primary viraemia, substantially increases the risk of vertical HIV transmission. Pre-exposure prophylaxis (PrEP) reduces the risk of HIV acquisition. Currently available products include oral tenofovir/emtricitabine (TDF/FTC) and tenofovir alafenamide (TAF)/FTC), long-acting cabotegravir (CAB-LA) and the dapivirine ring (DVR). All except oral TDF/FTC have limited safety data available for use in pregnant and breastfeeding women. The safety of new PrEP agents for pregnant women and the fetus, infant and child, either exposed in utero or during breastfeeding is an ongoing concern for health care workers and pregnant and breastfeeding women, particularly as the safety risk appetite for antiretroviral (ARV) agents used as PrEP is lower in pregnant and breastfeeding women who are HIV-uninfected, compared to women living with HIV taking ARVs as treatment. With the widespread rollout of TDF/FTC among pregnant women in South Africa and other low-middle income countries (LMIC) and the potential introduction of new PrEP agents for pregnant women, there is a need for safety surveillance systems to identify potential signals of risk to either the mother or fetus, measure the burden of such a risk, and where appropriate, provide specific reassurance to PrEP users. Safety data needs to be collected across the continuum of the product life cycle from pre-licensure into the post-marketing period, building a safety profile through both passive and active surveillance systems, recognising the strengths and limitations of each, and the potential for bias and confounding. Pharmacovigilance systems that aim to assess the risk of adverse birth outcomes in pregnant women exposed to PrEP and other agents need to consider the special requirements of pregnancy epidemiology to ensure that the data derived from surveillance are sufficiently robust to inform treatment policies. Here we review the known safety profiles of currently available PrEP candidates in women of child-bearing potential, pregnancy and breastfeeding and discuss pragmatic approaches for such surveillance in HIV-endemic LMICs.

T-cell responses induced by ChAdOx1 nCoV-19 (AZD1222) vaccine to wild-type severe acute respiratory syndrome coronavirus 2 among people with and without HIV in South Africa.

OBJECTIVES: This study aimed to investigate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T-cell responses 14 days after single-dose ChAdOx1 nCoV-19 (AZD1222) vaccination in black Africans with and without HIV in South Africa, as well as determine the effect of AZD1222 vaccination on cell-mediated immune responses in people with HIV (PWH) with prior SARS-CoV-2 infection. METHODS: A total of 70 HIV-uninfected people and 104 PWH were prospectively enrolled in the multicentre, randomized, double-blinded, placebo-controlled, phase Ib/IIa trial (COV005). Peripheral blood mononuclear cells (PBMCs) were collected from trial participants 14 days after receipt of first dose of study treatment (placebo or AZD1222 vaccine). T-cell responses against the full-length spike (FLS) glycoprotein of wild-type SARS-CoV-2 and mutated S-protein regions found in the Alpha, Beta and Delta variants were assessed using an ex-vivo ELISpot assay. RESULTS: Among AZD1222 recipients without preceding SARS-CoV-2 infection, T-cell responses to FLS of wild-type SARS-CoV-2 were similarly common in PWH and HIV-uninfected people (30/33, 90.9% vs. 16/21, 76.2%; P = 0.138); and magnitude of response was similar among responders (78 vs. 56 SFCs/106 PBMCs; P = 0.255). Among PWH, AZD1222 vaccinees with prior SARS-CoV-2 infection, displayed a heightened T-cell response magnitude compared with those without prior infection (186 vs. 78 SFCs/106 PBMCs; P = 0.001); and similar response rate (14/14, 100% vs. 30/33, 90.9%; P = 0.244). CONCLUSION: Our results indicate comparable T-cell responses following AZD1222 vaccination in HIV-uninfected people and PWH on stable antiretroviral therapy. Our results additionally show that hybrid immunity acquired through SARS-CoV-2 infection and AZD1222 vaccination, induce a heightened T-cell response.

Durability of ChAdOx1 nCoV-19 (AZD1222) vaccine and hybrid humoral immunity against variants including omicron BA.1 and BA.4 6 months after vaccination (COV005): a post-hoc analysis of a randomised, phase 1b-2a trial.

BACKGROUND: COVID-19 vaccine rollout is lagging in Africa, where there has been a high rate of SARS-CoV-2 infection. We aimed to evaluate the effect of SARS-CoV-2 infection before vaccination with the ChAdOx-nCoV19 (AZD1222) vaccine on antibody responses through to 180 days. METHODS: We did an unmasked post-hoc immunogenicity analysis after the first and second doses of AZD1222 in a randomised, placebo-controlled, phase 1b-2a study done in seven locations in South Africa. AZD1222 recipients who were HIV-uninfected, were stratified into baseline seropositive or seronegative groups using the serum anti-nucleocapsid (anti-N) immunoglobulin G (IgG) electroluminescence immunoassay to establish SARS-CoV-2 infection before the first dose of AZD1222. Binding IgG to spike (anti-S) and receptor binding domain (anti-RBD) were measured before the first dose (day 0), second dose (day 28), day 42, and day 180. Neutralising antibody (NAb) against SARS-CoV-2 variants D614G, beta, delta, gamma, and A.VOI.V2, and omicron BA1 and BA.4 variants, were measured by pseudovirus assay (day 28, day 42, and day 180). This trial is registered with ClinicalTrials.gov, NCT04444674, and the Pan African Clinicals Trials Registry, PACTR202006922165132. FINDINGS: Of 185 individuals who were randomly assigned to AZD1222, we included 91 individuals who were baseline seropositive and 58 who were baseline seronegative, in the final analysis. In the seropositive group, there was little change of anti-S IgG (and anti-RBD IgG) or neutralising antibody (NAb) titres at day 42 compared with at day 28. Anti-S (and anti-RBD) IgG geometric mean concentrations (GMCs) were higher throughout in the seropositive compared with the seronegative group, including at day 180 (GMCs 517·8 [95% CI 411·3-651·9] vs 82·1 [55·2-122·3] BAU/mL). Also D614G NAb geometric mean titres (GMTs) were higher in the seropositive group than the seronegative group, as was the percentage with titres of at least 185 (80% putative risk reduction threshold [PRRT] against wild-type-alpha COVID-19), including at day 180 (92·0% [74·0-99·0] vs 18·2% [2·3-51·8). Similar findings were observed for beta, A.VOI.V2, and gamma. For delta, BA.1, and BA.4, NAb GMTs and the proportion with titres above the PRRT were substantially higher in the seropositive compared with seronegative group at day 28 and day 42, but no longer differed between the groups by day 180. INTERPRETATION: A single dose of AZD1222 in the general African population, where COVID-19 vaccine coverage is low and SARS-CoV-2 seropositivity is 90%, could enhance the magnitude and quality of antibody responses to SARS-CoV-2. FUNDING: The Bill & Melinda Gates Foundation, the South African Medical Research Council, the UK Research and Innovation, the UK National Institute for Health Research, and the South African Medical Research Council. TRANSLATION: For the Zulu translation of the abstract see Supplementary Materials section.