Malaria Transmission Intensity Likely Modifies RTS, S/AS01 Efficacy Due to a Rebound Effect in Ghana, Malawi, and Gabon.

BACKGROUND: RTS,S/AS01 is the first malaria vaccine to be approved and recommended for widespread implementation by the World Health Organization (WHO). Trials reported lower vaccine efficacies in higher-incidence sites, potentially due to a "rebound" in malaria cases in vaccinated children. When naturally acquired protection in the control group rises and vaccine protection in the vaccinated wanes concurrently, malaria incidence can become greater in the vaccinated than in the control group, resulting in negative vaccine efficacies. METHODS: Using data from the 2009-2014 phase III trial (NCT00866619) in Lilongwe, Malawi; Kintampo, Ghana; and Lambaréné, Gabon, we evaluate this hypothesis by estimating malaria incidence in each vaccine group over time and in varying transmission settings. After estimating transmission intensities using ecological variables, we fit models with 3-way interactions between vaccination, time, and transmission intensity. RESULTS: Over time, incidence decreased in the control group and increased in the vaccine group. Three-dose efficacy in the lowest-transmission-intensity group (0.25 cases per person-year [CPPY]) decreased from 88.2% to 15.0% over 4.5 years, compared with 81.6% to -27.7% in the highest-transmission-intensity group (3 CPPY). CONCLUSIONS: These findings suggest that interventions, including the fourth RTS,S dose, that protect vaccinated individuals during the potential rebound period should be implemented for high-transmission settings.

Pharmacokinetics and Safety of 3 Months of Weekly Rifapentine and Isoniazid for Tuberculosis Prevention in Pregnant Women.

BACKGROUND: Pregnancy increases the risk of tuberculosis and its complications. A 3-month regimen of weekly isoniazid and rifapentine (3HP) is safe and effective for tuberculosis prevention in adults and children, including those with HIV, but 3HP has not been evaluated in pregnancy. METHODS: IMPAACT 2001 was a phase I/II trial evaluating the pharmacokinetics and safety of 3HP among pregnant women with indications for tuberculosis preventative therapy in Haiti, Kenya, Malawi, Thailand, and Zimbabwe (NCT02651259). Isoniazid and rifapentine were provided at standard doses (900 mg/week). Pharmacokinetic sampling was performed with the first (second/third trimester) and twelfth (third trimester/postpartum) doses. Nonlinear mixed-effects models were used to estimate drug population pharmacokinetics. RESULTS: Of 50 participants, 20 had HIV and were taking efavirenz-based antiretroviral therapy. Among women without HIV, clearance of rifapentine was 28% lower during pregnancy than postpartum (1.20 vs 1.53 L/hour, P < .001), with area under the concentration-time curve (AUCSS) of 786 and 673 mg × hour/L, respectively. In pregnant women with HIV, clearance was 30% higher than women without HIV (P < .001), resulting in lower AUCss (522 mg × hour/L); clearance did not change significantly between pregnancy and postpartum. Pregnancy did not impact isoniazid pharmacokinetics. There were no drug-related serious adverse events, treatment discontinuations, or tuberculosis cases in women or infants. CONCLUSIONS: 3HP does not require dose adjustment in pregnancy. Rifapentine clearance is higher among women with HIV, but all women achieved exposures of rifapentine and isoniazid associated with successful tuberculosis prevention. The data support proceeding with larger safety-focused studies of 3HP in pregnancy. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov, NCT02651259.

Chest radiography in children aged 2-59 months enrolled in the Innovative Treatments in Pneumonia (ITIP) project in Lilongwe Malawi: a secondary analysis.

BACKGROUND: Pneumonia is the leading infectious cause of death in children aged under 5 years in low- and middle-income countries (LMICs). World Health Organization (WHO) pneumonia diagnosis guidelines rely on non-specific clinical features. We explore chest radiography (CXR) findings among select children in the Innovative Treatments in Pneumonia (ITIP) project in Malawi in relation to clinical outcomes. METHODS: When clinically indicated, CXRs were obtained from ITIP-enrolled children aged 2 to 59 months with community-acquired pneumonia hospitalized with treatment failure or relapse. ITIP1 (fast-breathing pneumonia) and ITIP2 (chest-indrawing pneumonia) trials enrolled children with non-severe pneumonia while ITIP3 enrolled children excluded from ITIP1 and ITIP2 with severe pneumonia and/or selected comorbidities. A panel of trained pediatricians classified the CXRs using the standardized WHO CXR research methodology. We analyzed the relationship between CXR classifications, enrollee characteristics, and outcomes. RESULTS: Between March 2016 and June 2018, of 114 CXRs obtained, 83 met analysis criteria with 62.7% (52/83) classified as having significant pathology per WHO standardized interpretation. ITIP3 (92.3%; 12/13) children had a higher proportion of CXRs with significant pathology compared to ITIP1 (57.1%, 12/21) and ITIP2 (57.1%, 28/49) (p-value = 0.008). The predominant pathological CXR reading was "other infiltrates only" in ITIP1 (83.3%, 10/12) and ITIP2 (71.4%, 20/28), while in ITIP3 it was "primary endpoint pneumonia"(66.7%, 8/12,; p-value = 0.008). The percent of CXRs with significant pathology among children clinically cured (60.6%, 40/66) vs those not clinically cured (70.6%, 12/17) at Day 14 was not significantly different (p-value = 0.58). CONCLUSIONS: In this secondary analysis we observed that ITIP3 children with severe pneumonia and/or selected comorbidities had a higher frequency of CXRs with significant pathology, although these radiographic findings had limited relationship to Day 14 outcomes. The proportion of CXRs with "primary endpoint pneumonia" was low. These findings add to existing data that additional diagnostics and prognostics are important for improving the care of children with pneumonia in LMICs. TRIAL REGISTRATION: ITIP1, ITIP2, and ITIP3 were registered with ClinicalTrials.gov ( NCT02760420 , NCT02678195 , and NCT02960919 , respectively).

African Multi-Site 2-Year Neuropsychological Study of School-Age Children Perinatally Infected, Exposed, and Unexposed to Human Immunodeficiency Virus.

BACKGROUND: Children living with human immunodeficiency virus (HIV) are at neuropsychological risk for cognitive and motor dysfunction. However, few prospective, multi-site studies have evaluated neuropsychological outcomes longitudinally among perinatally infected African children who received early antiretroviral treatment (ART). METHODS: We enrolled 611 children aged 5 to 11 years at 6 sites (South Africa [3], Zimbabwe, Malawi, Uganda). Of these, there were 246 children living with HIV (HIV+) who were initiated on ART before 3 years of age in a prior clinical trial comparing nevirapine to lopinavir/ritonavir (International Maternal Pediatric Adolescent Acquired Immunodeficiency Syndrome Clinical Trials [IMPAACT] P1060); 183 age-matched, exposed but uninfected (HEU) children; and 182 unexposed and uninfected (HUU) children. They were compared across 3 assessment time points (Weeks 0, 48, and 96) on cognitive ability (Kaufman Assessment Battery for Children, second edition [KABC-II]), attention/impulsivity (Tests of Variables of Attention [TOVA]), motor proficiency (Bruininks-Oseretsky Test, second edition [BOT-2]), and on the Behavior Rating Inventory of Executive Function (BRIEF). The cohorts were compared using linear mixed models, adjusting for site, child's age and sex, and selected personal/family control variables. RESULTS: The HIV+ cohort performed significantly worse than the HEU and HUU cohorts for all KABC-II, TOVA, and BOT-2 performance outcomes across all 3 time points (P values < .001). The HUU and HEU cohorts were comparable. For the KABC-II planning/reasoning subtests, the HIV+ children showed less improvement over time than the HUU and HEU groups. The groups did not differ significantly on the BRIEF. CONCLUSIONS: Despite initiation of ART in early childhood and good viral suppression at the time of enrollment, the HIV+ group had poorer neuropsychological performance over time, with the gap progressively worsening in planning/reasoning. This can be debilitating for self-management in adolescence.

Association between caregiver depression symptoms and child executive functioning. Results from an observational study carried out in four sub-Saharan countries.

Depressive symptoms among HIV-positive (HIV+) women may negatively impact their health and possibly that of their young children through risk of compromised caregiving. We evaluated how depression symptoms in predominantly (97%) female caregivers relate to neurodevelopmental outcomes in their HIV affected children. Data come from the IMPAACT P1104s Study, an observational cohort across six sites in four countries: Zimbabwe, South Africa, Uganda and Malawi. Participants (n = 611) were 5-11-year-old children with HIV (HIV), HIV exposed uninfected (HEU), or HIV unexposed uninfected (HUU). Primary caregivers were assessed for depression with the Hopkins Symptom Checklist (HSCL) and children with Behavior Rating Inventory for Executive Function (BRIEF) parent-report, Kauffman Assessment Battery for Children II (KABC), Bruininks-Oseretsky Test of Motor Proficiency 2nd Ed. (BOT-2), Test of Variables of Attention (TOVA), Multiple Indicators Cluster Survey, Child Disability and Development scales (MICS-4). Caregivers with higher depression scores (>1.75 mean HSCL score) reported more executive function problems in their children, regardless of HIV status. All executive function scores were significantly (p < 0.001) associated with depressive symptomatology at baseline and across time. Caregiver depressive symptomatology was not associated with other assessed neurocognitive outcomes. These results highlight the potential impact of caregiver depression on child behavioral outcomes.

Environmental modifiers of RTS,S/AS01 malaria vaccine efficacy in Lilongwe, Malawi.

BACKGROUND: RTS,S/AS01 is the first vaccine against malaria to undergo pilot implementation, beginning in 2019 and vaccinating 360,000 children per year in Malawi, Ghana, and Kenya. The four-dose vaccine is given as a primary three-dose series with a fourth dose given approximately 18 months later. The efficacy of RTS,S/AS01 was variable among the 11 sites participating in the 2009-2014 phase III trial (MALARIA-055, NCT00866619), possibly due to differences in transmission intensity. However, a within-site examination of environmental factors related to transmission intensity and their impact on vaccine efficacy has yet to be conducted. METHODS: We implemented the phase III RTS,S/AS01 trial at the Malawi site, which enrolled 1578 infants (6-12 weeks) and children (5-17 months) living in the Lilongwe District in Central Malawi and followed them for 3 years between 2009 and 2014. A global positioning system survey and an ecological questionnaire were conducted to collect participant household locations and characteristics, while additional data on background malaria prevalence were obtained from a concurrent Malaria Transmission Intensity (MTI) survey. Negative binomial regression models were used to assess whether the efficacy of the vaccine varied by estimated background malaria prevalence, household roof type, or amount of nearby vegetation. RESULTS: Vaccine efficacy did not significantly vary by estimated malaria prevalence or by roof type. However, increased vegetation cover was associated with an increase in the efficacy of the three-dose primary RTS,S/AS01 series in the 18 months before the fourth dose and a decrease in the efficacy of the primary vaccine series in the second 18 months following, if the fourth dose was not given. Vegetation cover did not alter the efficacy of the fourth dose in a statistically or practically significant manner. CONCLUSIONS: Vegetation coverage in this study site might be a proxy for nearness to rivers or branching, shallow wetlands called "dambos" which could serve as breeding sites for mosquitoes. We observed statistically significant modification of the efficacy of RTS,S/AS01 by forest cover, suggesting that initial vaccine efficacy and the importance of the fourth dose varies based on ecological context. TRIAL REGISTRATION: Efficacy of GSK Biologicals' Candidate Malaria Vaccine (257049) Against Malaria Disease Caused by P. falciparum Infection in Infants and Children in Africa. NCT00866619 prospectively registered 20 March 2009.

Real-world experience using hydroxyurea in children with sickle cell disease in Lilongwe, Malawi.

INTRODUCTION: Sickle cell disease (SCD) is among the most common inherited hematologic diseases in sub-Saharan Africa (SSA). Historically, hydroxyurea administration in SSA has been restricted due to limited region-specific evidence for safety and efficacy. METHODS: We conducted a prospective observational cohort study of pediatric patients with SCD in Malawi. From January 2015 to November 2017, hydroxyurea at doses of 10-20 mg/kg/day was administered to children with clinically severe disease (targeted use policy). From December 2017 to July 2018, hydroxyurea was prescribed to all patients (universal use policy). RESULTS: Of 187 patients with SCD, seven (3.7%) died and 23 (12.3%) were lost to follow-up. The majority (135, 72.2%) were prescribed hydroxyurea, 59 (43.7%) under the targeted use policy and 76 (56.3%) under the universal use policy. There were no documented severe toxicities. Under the targeted use policy, children with SCD demonstrated absolute decreases in the rates of hospitalization (-4.1 per 1000 person-days; -7.2, -1.0; P = .004), fevers (-4.2 per 1000 person-days; -7.2, -1.1; P = .002), transfusions (-2.3 per 1000 person-days; 95% confidence interval: -4.9, 0.3; P = .06), and annual school absenteeism (-51.2 per person-year; -60.1, -42.3; P < .0001) within 6 months of hydroxyurea commencement. CONCLUSION: We successfully implemented universal administration of hydroxyurea to children with SCD at a tertiary hospital in Malawi. Similar to recently reported trials, hydroxyurea was safe and effective during routine programmatic experience, with clinical benefits particularly among high-risk children. This highlights the importance of continued widespread scale-up of hydroxyurea within SCD programs across SSA.

Nephrin as a biomarker of sickle cell glomerulopathy in Malawi.

BACKGROUND: Glomerulopathy is an increasingly identified complication in young patients with sickle cell disease (SCD). Hyperfiltration and albuminuria followed by declining glomerular filtration rates and eventual end-stage renal disease (ESRD) is assumed to be the typical progression of glomerular disease. There are only a few reported biomarkers to identify early-stage renal disease in SCD. PROCEDURES: We detail the renal profile of 101 children with SCD in Malawi and propose a novel urinary biomarker for the identification of early renal disease. RESULTS: Among children with sickle cell anemia, 24.8% had a urine albumin-creatinine ratio of 30 mg/g or above. In univariate analysis, only patients with higher urinary nephrin, a urinary marker of glomerular injury, had significantly greater odds of having albuminuria. In multivariable analysis, nephrin remained significantly associated with albuminuria. A nephrin-creatinine ratio (NCR) cut-point of 622 ng/mg, the 50th percentile, was associated with a 45.8 times greater odds of having albuminuria in children with nephrinuria above this value. Further analysis revealed this urinary NCR cut-point to have 96% sensitivity, 64% specificity, 47% positive predictive value, and 98% negative predictive value for the presence of albuminuria. CONCLUSIONS: These data suggest that a substantial number of children with SCD in Malawi have renal disease and could be at risk for worsening nephropathy and ESRD as they age. Our data suggest that urinary nephrin could be utilized as an early marker of glomerular disease in SCD.

Nevirapine- Versus Lopinavir/Ritonavir-Based Antiretroviral Therapy in HIV-Infected Infants and Young Children: Long-term Follow-up of the IMPAACT P1060 Randomized Trial.

BACKGROUND: The International Maternal Pediatric Adolescent AIDS Clinical Trials Network (IMPAACT) P1060 study demonstrated short-term superiority of lopinavir/ritonavir (LPV/r) over nevirapine (NVP) in antiretroviral therapy (ART), regardless of prior NVP exposure. However, NVP-based ART had a marginal benefit in CD4 percentage (CD4%) and growth. We compared 5-year outcomes from this clinical trial. METHODS: Human immunodeficiency virus (HIV)-infected, ART-eligible children were enrolled into 2 cohorts based on prior NVP exposure and randomized to NVP- or LPV/r-based ART. The data safety monitoring board recommended unblinding results in both cohorts due to superiority of LPV/r for the primary endpoint: stopping randomized treatment, virologic failure (VF), or death by 6 months. Participants were offered a switch in regimens (if on NVP) and continued observational follow-up. We compared time to VF or death, death, and CD4% and growth changes using intention-to-treat analyses. Additionally, inverse probability weights were used to account for treatment switching and censoring. RESULTS: As of September 2014, 329 of the 451 (73%) enrolled participants were still in follow-up (median, 5.3 years; interquartile range [IQR], 4.3-6.4), with 52% on NVP and 88% on LPV/r as originally randomized. NVP arm participants had significantly higher risk of VF or death (adjusted hazard ratio [aHR], 1.90; 95% confidence interval [CI], 1.37-2.65) but not death alone (aHR, 1.65; 95% CI, .72-3.76) compared with participants randomized to LPV/r. Mean CD4% was significantly higher in the NVP arm up to 1 year after ART initiation, but not beyond. Mean weight-for-age z scores were marginally higher in the NVP arm, but height-for-age z scores did not differ. Similar trends were observed in sensitivity analyses. CONCLUSIONS: These findings support the current World Health Organization recommendation of LPV/r in first-line ART regimens for HIV-infected children. CLINICAL TRIALS REGISTRATION: NCT00307151.

Nevirapine versus ritonavir-boosted lopinavir for HIV-infected children.

BACKGROUND: Nevirapine-based antiretroviral therapy is the predominant (and often the only) regimen available for children in resource-limited settings. Nevirapine resistance after exposure to the drug for prevention of maternal-to-child human immunodeficiency virus (HIV) transmission is common, a problem that has led to the recommendation of ritonavir-boosted lopinavir in such settings. Regardless of whether there has been prior exposure to nevirapine, the performance of nevirapine versus ritonavir-boosted lopinavir in young children has not been rigorously established. METHODS: In a randomized trial conducted in six African countries and India, we compared the initiation of HIV treatment with zidovudine, lamivudine, and either nevirapine or ritonavir-boosted lopinavir in HIV-infected children 2 to 36 months of age who had no prior exposure to nevirapine. The primary end point was virologic failure or discontinuation of treatment by study week 24. RESULTS: A total of 288 children were enrolled; the median percentage of CD4+ T cells was 15%, and the median plasma HIV type 1 (HIV-1) RNA level was 5.7 log(10) copies per milliliter. The percentage of children who reached the primary end point was significantly higher in the nevirapine group than in the ritonavir-boosted lopinavir group (40.8% vs. 19.3%; P<0.001). Among the nevirapine-treated children with virologic failure for whom data on resistance were available, more than half (19 of 32) had resistance at the time of virologic failure. In addition, the time to a protocol-defined toxicity end point was shorter in the nevirapine group (P=0.04), as was the time to death (P=0.06). CONCLUSIONS: Outcomes were superior with ritonavir-boosted lopinavir among young children with no prior exposure to nevirapine. Factors that may have contributed to the suboptimal results with nevirapine include elevated viral load at baseline, selection for nevirapine resistance, background regimen of nucleoside reverse-transcriptase inhibitors, and the standard ramp-up dosing strategy. The results of this trial present policymakers with difficult choices. (Funded by the National Institute of Allergy and Infectious Diseases and others; P1060 ClinicalTrials.gov number, NCT00307151.).

Antiretroviral treatment for children with peripartum nevirapine exposure.

BACKGROUND: Single-dose nevirapine is the cornerstone of the regimen for prevention of mother-to-child transmission of human immunodeficiency virus (HIV) in resource-limited settings, but nevirapine frequently selects for resistant virus in mothers and children who become infected despite prophylaxis. The optimal antiretroviral treatment strategy for children who have had prior exposure to single-dose nevirapine is unknown. METHODS: We conducted a randomized trial of initial therapy with zidovudine and lamivudine plus either nevirapine or ritonavir-boosted lopinavir in HIV-infected children 6 to 36 months of age, in six African countries, who qualified for treatment according to World Health Organization (WHO) criteria. Results are reported for the cohort that included children exposed to single-dose nevirapine prophylaxis. The primary end point was virologic failure or discontinuation of treatment by study week 24. Enrollment in this cohort was terminated early on the recommendation of the data and safety monitoring board. RESULTS: A total of 164 children were enrolled. The median percentage of CD4+ lymphocytes was 19%; a total of 56% of the children had WHO stage 3 or 4 disease. More children in the nevirapine group than in the ritonavir-boosted lopinavir group reached a primary end point (39.6% vs. 21.7%; weighted difference, 18.6 percentage-points; 95% confidence interval, 3.7 to 33.6; nominal P=0.02). Baseline resistance to nevirapine was detected in 18 of 148 children (12%) and was predictive of treatment failure. No significant between-group differences were seen in the rate of adverse events. CONCLUSIONS: Among children with prior exposure to single-dose nevirapine for perinatal prevention of HIV transmission, antiretroviral treatment consisting of zidovudine and lamivudine plus ritonavir-boosted lopinavir resulted in better outcomes than did treatment with zidovudine and lamivudine plus nevirapine. Since nevirapine is used for both treatment and perinatal prevention of HIV infection in resource-limited settings, alternative strategies for the prevention of HIV transmission from mother to child, as well as for the treatment of HIV infection, are urgently required. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00307151.).

Antiretroviral choice and severe disease predict poorer neuropsychological outcomes in HIV+ children from Africa.

Background: The International Maternal Pediatric Adolescent AIDS Clinical Trials Network (IMPAACT) P1104s study evaluated neuropsychological outcomes over 96 weeks in children living with HIV (CLHIV) aged 5-11 years at 6 Sub-Saharan African sites to explore associations between HIV-illness related biomarkers and neuropsychological outcomes. Methods: Children living with HIV had participated in IMPAACT P1060, which compared efficacy of nevirapine versus lopinavir/ritonavir in children initiating ART at <3 years of age. At age 5-11, neuropsychological evaluations of KABC cognitive ability, TOVA attention-impulsivity and BOT-2 motor domains were assessed and repeated after 48 and 96 weeks. Clinical, antiretroviral therapy (ART) and laboratory (immunological and virological) parameters were used to predict neuropsychological outcomes using linear mixed-effects multivariable regression models, controlling for child and caregiver characteristics. Results: 246 CLHIV (45% male, mean age at initial neuropsychological evaluation 7.1 yrs [SD 1.2]) began ART at a median age 14.9 months (IQR 8.2, 25.2). Nadir CD4 percentage was 14.7% (IQR 11.0, 19.5); the median peak viral load (VL) was 750 000 copies/ml (IQR 366 000, 750 000) and 63% had ≥WHO stage 3 clinical disease; 164 (67%) were on lopinavir/ritonavir, 71 (29%) were on nevirapine and 7 (3%) were on efavirenz. Other antiretrovirals were similar. Nevirapine at P1104s study start or later was associated with poorer neuropsychological scores across all domains except Global Executive Composite, even when controlling for nadir CD4 percent and time-varying HIV VL. Other predictors of poorer scores in KABC domains included low birth weight, WHO stage 4 disease and serious illness history and elevated VL was associated with worse BOT-2 scores. Conclusion: Children receiving nevirapine had poorer neuropsychological scores than those on lopinavir/ritonavir. Antiretroviral choice might adversely impact neuropsychological performance. In addition, low birth weight and markers of severe HIV disease: advanced WHO clinical HIV disease, history of serious illness and an elevated VL, were associated with lower neuropsychological scores.

Assessment of severe malaria in a multicenter, phase III, RTS, S/AS01 malaria candidate vaccine trial: case definition, standardization of data collection and patient care.

BACKGROUND: An effective malaria vaccine, deployed in conjunction with other malaria interventions, is likely to substantially reduce the malaria burden. Efficacy against severe malaria will be a key driver for decisions on implementation. An initial study of an RTS, S vaccine candidate showed promising efficacy against severe malaria in children in Mozambique. Further evidence of its protective efficacy will be gained in a pivotal, multi-centre, phase III study. This paper describes the case definitions of severe malaria used in this study and the programme for standardized assessment of severe malaria according to the case definition. METHODS: Case definitions of severe malaria were developed from a literature review and a consensus meeting of expert consultants and the RTS, S Clinical Trial Partnership Committee, in collaboration with the World Health Organization and the Malaria Clinical Trials Alliance. The same groups, with input from an Independent Data Monitoring Committee, developed and implemented a programme for standardized data collection.The case definitions developed reflect the typical presentations of severe malaria in African hospitals. Markers of disease severity were chosen on the basis of their association with poor outcome, occurrence in a significant proportion of cases and on an ability to standardize their measurement across research centres. For the primary case definition, one or more clinical and/or laboratory markers of disease severity have to be present, four major co-morbidities (pneumonia, meningitis, bacteraemia or gastroenteritis with severe dehydration) are excluded, and a Plasmodium falciparum parasite density threshold is introduced, in order to maximize the specificity of the case definition. Secondary case definitions allow inclusion of co-morbidities and/or allow for the presence of parasitaemia at any density. The programmatic implementation of standardized case assessment included a clinical algorithm for evaluating seriously sick children, improvements to care delivery and a robust training and evaluation programme for clinicians. CONCLUSIONS: The case definition developed for the pivotal phase III RTS, S vaccine study is consistent with WHO recommendations, is locally applicable and appropriately balances sensitivity and specificity in the diagnosis of severe malaria. Processes set up to standardize severe malaria data collection will allow robust assessment of the efficacy of the RTS, S vaccine against severe malaria, strengthen local capacity and benefit patient care for subjects in the trial. TRIAL REGISTRATION: Clinicaltrials.gov NCT00866619.

Impacts of Ecology, Parasite Antigenic Variation, and Human Genetics on RTS,S/AS01e Malaria Vaccine Efficacy.

PURPOSE OF REVIEW: Global malaria elimination has little chance of success without an effective vaccine. The first malaria vaccine, RTS,S/AS01e, demonstrated moderate efficacy against clinical malaria in phase III trials and is undergoing large-scale effectiveness trials in Africa. Importantly, the vaccine did not perform equally well between phase III study sites. Though reasons for the moderate efficacy and this variation are unclear, various mechanisms have been suggested. This review summarizes the recent literature on such mechanisms, with a focus on those involving landscape ecology, parasite antigenic variation, and human host genetic differences. RECENT FINDINGS: Transmission intensity may have a role pre- and post-vaccination in modulating immune responses to the vaccine. Furthermore, malaria incidence may "rebound" in vaccinated populations living in high transmission intensity settings. There is growing evidence that both genetic variation in the parasite circumsporozoite protein and variation of human host genetic factors affect RTS,S vaccine efficacy. These genetic factors may be interacting in complex ways to produce variation in the natural and vaccine-induced immune responses that protect against malaria. SUMMARY: Due to the modest efficacy of RTS,S/AS01e, the combinations of factors (ecological, parasite, human host) impacting its effectiveness must be clearly understood, as this information will be critical for implementation policy and future vaccine designs.

Prospective Newborn Screening for Sickle Cell Disease and Other Inherited Blood Disorders in Central Malawi.

Objectives: Newborn screening in the United States and Europe allows early identification of congenital disorders but does not yet exist in most low-resource settings, especially in sub-Saharan Africa. Newborn screening can identify multiple inherited hematological disorders, but feasibility and effectiveness for Africa are not fully determined. Methods: Surplus dried blood spot collected in Central Malawi through the HIV Early Infant Diagnosis surveillance program were repurposed and tested by isoelectric focusing for sickle cell disease and trait. Additional genetic testing identified G6PD deficiency and alpha thalassemia. Results: Testing of 10,529 cards revealed an overall sickle cell trait prevalence of 7.0% (range 3.9-9.7% by district); 10 of 14 infants identified with sickle cell disease (prevalence 0.1%) were located and received care at a specialized clinic. Subsequent testing of 1,329 randomly selected cards identified alpha thalassemia trait in 45.7% of samples, and G6PD deficiency in 20.4% of males and 3.4% of females, with 29.0% of females as heterozygous carriers. Conclusion: Inherited hematological disorders are common in Central Malawi; early identification through newborn screening can improve clinical outcomes and should be supported throughout Africa.

IMPAACT 2016: Operationalizing HIV Intervention Adaptations to Inform the Science and Outcomes of Implementation.

Introduction: Uptake of evidence-based interventions for adolescents and young adults living with HIV (AYA-LWH) in sub-Saharan Africa (SSA) is complex, and cultural differences necessitate local adaptations to enhance effective implementation. Few models exist to guide intervention tailoring, yet operationalizing strategies is critical to inform science and implementation outcomes, namely acceptability, appropriateness, feasibility, fidelity, and sustainability. This paper describes operationalizing the ADAPT-ITT framework applied to a manualized trauma-informed cognitive behavioral therapy (TI-CBT) intervention addressing mental and sexual health for AYA-LWH in SSA in preparation for a randomized controlled trial (RCT). Methods: Phase 1 of the RCT focused on operationalizing ADAPT-ITT steps 3-7 to tailor the intervention for use in eight sites across Botswana, Malawi, South Africa, and Zimbabwe. Well-defined processes were developed to supplement the general guidelines for each step to provide clear, consistent direction on how to prepare and conduct each step, including documenting, assessing, and determining adaptations, while maintaining intervention fidelity. The processes provided efficient standardized step-by-step progression designed for future replication. All sites participated in Phase 1 using the created tools and strategies to translate and present the TI-CBT to community stakeholders for feedback informing local adaptations. Results: The research team developed and operationalized materials guiding adaptation. A translation review process verified local adaptability, maintained core concepts, and revealed differing interpretations of words, idioms, and culturally acceptable activities. Strategically designed tools comprised of feedback and translation verification forms resulted in meticulous management of adaptations. Robust collaborations between investigators, research managers, site personnel, and topical experts maximized multidisciplinary expertise, resulting in ~10-15 personnel per site facilitating, collecting, assessing, and integrating local feedback. Processes and tools operationalized in steps 3-7 effectively addressed implementation outcomes during community engagements (n = 108), focus groups (n = 5-8 AYA-LWH and caregivers per group), and strategic training of youth leaders. Discussion: This paper offers a novel generalizable approach using well-defined processes to guide intervention adaptation building on the ADAPT-ITT framework. The processes strengthen the science of implementation and provide much-needed specificity in adaptation steps to optimize and sustain real-world impact and help researchers and community stakeholders maximize existing infrastructure, culture, and resources to inform implementation strategies.

Pharmacokinetics and Safety of Zidovudine, Lamivudine, and Lopinavir/Ritonavir in HIV-infected Children With Severe Acute Malnutrition in Sub-Saharan Africa: IMPAACT Protocol P1092.

BACKGROUND: Severe acute malnutrition (SAM) may alter the pharmacokinetics (PK), efficacy, and safety of antiretroviral therapy. The phase IV study, IMPAACT P1092, compared PK, safety, and tolerability of zidovudine (ZDV), lamivudine (3TC), and lopinavir/ritonavir (LPV/r) in children with and without SAM. MATERIALS AND METHODS: Children living with HIV 6 to <36 months of age with or without World Health Organization (WHO)-defined SAM received ZDV, 3TC, and LPV/r syrup for 48 weeks according to WHO weight band dosing. Intensive PK sampling was performed at weeks 1, 12, and 24. Plasma drug concentrations were measured using liquid chromatography tandem mass spectrometry. Steady-state mean area under the curve (AUC0-12h) and clearance (CL/F) for each drug were compared. Grade ≥3 adverse events were compared between cohorts. RESULTS: Fifty-two children were enrolled across 5 sites in Africa with 44% (23/52) female, median age 19 months (Q1, Q3: 13, 25). Twenty-five children had SAM with entry median weight-for-height Z-score (WHZ) -3.4 (IQR -4.0, -3.0) and 27 non-SAM had median WHZ -1.0 (IQR -1.8, -0.1). No significant differences in mean AUC0-12h or CL/F were observed (P ≥ 0.09) except for lower 3TC AUC0-12h (GMR, 0.60; 95% CI, 0.4-1.0; P = 0.047) at week 12, higher ZDV AUC0-12h (GMR, 1.52; 1.2-2.0; P = 0.003) at week 24 in the SAM cohort compared with non-SAM cohort. Treatment-related grade ≥3 events did not differ significantly between cohorts (24.0% vs. 25.9%). CONCLUSION: PK and safety findings for ZDV, 3TC, and LPV/r support current WHO weight band dosing of syrup formulations in children with SAM.

Case reduction and cost-effectiveness of the RTS,S/AS01 malaria vaccine alongside bed nets in Lilongwe, Malawi.

BACKGROUND: RTS,S/AS01, the most advanced vaccine against malaria, is now undergoing pilot implementation in Malawi, Ghana, and Kenya where an estimated 360,000 children will be vaccinated each year. In this study we evaluate RTS,S/AS01 alongside bed net use and estimate cost-effectiveness. METHODS: RTS,S/AS01 phase III trial and bed net prevalence data were used to determine the effect of vaccination in the urban/periurban and rural areas of Lilongwe, Malawi. Cost data were used to calculate the cost-effectiveness of various interventions over three years. FINDINGS: Since bed nets reduce malaria incidence and homogeneous vaccine efficacy was assumed, participants without bed nets received greater relative benefit from vaccination with RTS,S/AS01 than participants with bed nets. Similarly, since malaria incidence in rural Lilongwe is higher than in urban Lilongwe, the impact and cost-effectiveness of vaccine interventions is increased in rural areas. In rural Lilongwe, we estimated that vaccinating one child without a bed net would prevent 2·59 (1·62 to 3·38) cases of malaria over three years, corresponding to a cost of $10·08 (7·71 to 16·13) per case averted. Alternatively, vaccinating one child with a bed net would prevent 1·59 (0·87 to 2·57) cases, corresponding to $16·43 (10·16 to 30·06) per case averted. Providing RTS,S/AS01 to 30,000 children in rural Lilongwe was estimated to cost $782,400 and to prevent 58,611 (35,778 to 82,932) cases of malaria over a three-year period. Joint interventions providing both vaccination and bed nets (to those without them) were estimated to prevent additional cases of malaria and to be similarly cost-effective, compared to vaccine-only interventions. INTERPRETATION: To maximize malaria prevention, vaccination and bed net distribution programs could be integrated. FUNDING: Impacts of Environment, Host Genetics and Antigen Diversity on Malaria Vaccine Efficacy (1R01AI137410-01).

Safety and immunogenicity of the RTS,S/AS01 malaria vaccine in infants and children identified as HIV-infected during a randomized trial in sub-Saharan Africa.

BACKGROUND: We assessed the safety and immunogenicity of the RTS,S/AS01 malaria vaccine in a subset of children identified as HIV-infected during a large phase III randomized controlled trial conducted in seven sub-Saharan African countries. METHODS: Infants 6-12 weeks and children 5-17 months old were randomized to receive 4 RTS,S/AS01 doses (R3R group), 3 RTS,S/AS01 doses plus 1 comparator vaccine dose (R3C group), or 4 comparator vaccine doses (C3C group) at study months 0, 1, 2 and 20. Infants and children with WHO stage III/IV HIV disease were excluded but HIV testing was not routinely performed on all participants; our analyses included children identified as HIV-infected based on medical history or clinical suspicion and confirmed by polymerase chain reaction or antibody testing. Serious adverse events (SAEs) and anti-circumsporozoite (CS) antibodies were assessed. RESULTS: Of 15459 children enrolled in the trial, at least 1953 were tested for HIV and 153 were confirmed as HIV-infected (R3R: 51; R3C: 54; C3C: 48). Among these children, SAEs were reported for 92.2% (95% CI: 81.1-97.8) in the R3R, 85.2% (72.9-93.4) in the R3C and 87.5% (74.8-95.3) in the C3C group over a median follow-up of 39.3, 39.4 and 38.3 months, respectively. Fifteen HIV-infected participants in each group (R3R: 29.4%, R3C: 27.8%, C3C: 31.3%) died during the study. No deaths were considered vaccination-related. In a matched case-control analysis, 1 month post dose 3 anti-CS geometric mean antibody concentrations were 193.3 EU/mL in RTS,S/AS01-vaccinated HIV-infected children and 491.5 EU/mL in RTS,S/AS01-vaccinated immunogenicity controls with unknown or negative HIV status (p = 0.0001). CONCLUSIONS: The safety profile of RTS,S/AS01 in HIV-infected children was comparable to that of the comparator (meningococcal or rabies) vaccines. RTS,S/AS01 was immunogenic in HIV-infected children but antibody concentrations were lower than in children with an unknown or negative HIV status. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT00866619.