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Mycobacterium tuberculosis continues to cause substantial illness globally. In this phase 2b randomized trial, BCG revaccination did not prevent sustained M. tuberculosis infection in IGRA-negative, HIV-negative adolescents.

Vaccination that prevents tuberculosis (TB) disease, particularly in adolescents, would have the greatest impact on the global TB epidemic. Safety, reactogenicity and immunogenicity of the vaccine candidate M72/AS01E was evaluated in healthy, HIV-negative adolescents in a TB endemic region, regardless of Mycobacterium tuberculosis (M.tb) infection status. In a phase II, double-blind randomized, controlled study (NCT00950612), two doses of M72/AS01E or placebo were administered intramuscularly, one month apart. Participants were followed-up post-vaccination, for 6 months. M72-specific immunogenicity was evaluated by intracellular cytokine staining analysis of T cells and NK cells by flow cytometry. No serious adverse events were recorded. M72/AS01E induced robust T cell and antibody responses, including antigen-dependent NK cell IFN-γ production. CD4 and CD8 T cell responses were sustained at 6 months post vaccination. Irrespective of M.tb infection status, vaccination induced a high frequency of M72-specific CD4 T cells expressing multiple combinations of Th1 cytokines, and low level IL-17. We observed rapid boosting of immune responses in M.tb-infected participants, suggesting natural infection acts as a prime to vaccination. The clinically acceptable safety and immunogenicity profile of M72/AS01E in adolescents living in an area with high TB burden support the move to efficacy trials.

Prophylactic zinc supplementation has been shown to reduce diarrhea and respiratory illness in children in many developing countries, but its efficacy in children in Africa is uncertain. To determine if zinc, or zinc plus multiple micronutrients, reduces diarrhea and respiratory disease prevalence. Randomized, double-blind, controlled trial. Rural community in South Africa. THREE COHORTS: 32 HIV-infected children; 154 HIV-uninfected children born to HIV-infected mothers; and 187 HIV-uninfected children born to HIV-uninfected mothers. Children received either 1250 IU of vitamin A; vitamin A and 10 mg of zinc; or vitamin A, zinc, vitamins B1, B2, B6, B12, C, D, E, and K and copper, iodine, iron, and niacin starting at 6 months and continuing to 24 months of age. Homes were visited weekly. Primary outcome was percentage of days of diarrhea per child by study arm within each of the three cohorts. Secondary outcomes were prevalence of upper respiratory symptoms and percentage of children who ever had pneumonia by maternal report, or confirmed by the field worker. Among HIV-uninfected children born to HIV-infected mothers, median percentage of days with diarrhea was 2.3% for 49 children allocated to vitamin A; 2.5% in 47 children allocated to receive vitamin A and zinc; and 2.2% for 46 children allocated to multiple micronutrients (P = 0.852). Among HIV-uninfected children born to HIV-uninfected mothers, median percentage of days of diarrhea was 2.4% in 56 children in the vitamin A group; 1.8% in 57 children in the vitamin A and zinc group; and 2.7% in 52 children in the multiple micronutrient group (P = 0.857). Only 32 HIV-infected children were enrolled, and there were no differences between treatment arms in the prevalence of diarrhea. The prevalence of upper respiratory symptoms or incidence of pneumonia did not differ by treatment arms in any of the cohorts. When compared with vitamin A alone, supplementation with zinc, or with zinc and multiple micronutrients, did not reduce diarrhea and respiratory morbidity in rural South African children. ClinicalTrials.gov NCT00156832.

Efforts to reduce risk of tuberculosis disease in children include development of effective vaccines. Our aim was to test safety and immunogenicity of the new adenovirus 35-vectored tuberculosis vaccine candidate AERAS-402 in infants, administered as a boost following a prime with the Bacille Calmette-Guerin vaccine. In a phase 1 randomised, double-blind, placebo-controlled, dose-escalation trial, BCG-vaccinated infants aged 6–9 months were sequentially assigned to four study groups, then randomized to receive an increasing dose-strength of AERAS-402, or placebo. The highest dose group received a second dose of vaccine or placebo 56 days after the first. The primary study outcome was safety. Whole blood intracellular cytokine staining assessed immunogenicity. Forty-two infants received AERAS-402 and 15 infants received placebo. During follow-up of 182 days, an acceptable safety profile was shown with no serious adverse events or discontinuations related to the vaccine. AERAS-402 induced a specific T cell response. A single dose of AERAS-402 induced CD4T cells predominantly expressing single IFN-γ whereas two doses induced CD4T cells predominantly expressing IFN-γ, TNF-α and IL-2 together. CD8T cells were induced and were more likely to be present after 2 doses of AERAS-402. AERAS-402 was safe and immunogenic in healthy infants previously vaccinated with BCG at birth. Administration of the highest dose twice may be the most optimal vaccination strategy, based on the induced immunity. Multiple differences in T cell responses when infants are compared with adults vaccinated with AERAS-402, in the same setting and using the same whole blood intracellular cytokine assay, suggest specific strategies may be important for vaccination for each population.

Targeted preventive therapy for individuals at highest risk of incident tuberculosis might impact the epidemic by interrupting transmission. We tested performance of a transcriptomic signature of tuberculosis (RISK11) and efficacy of signature-guided preventive therapy in parallel, using a hybrid three-group study design. Adult volunteers aged 18–59 years were recruited at five geographically distinct communities in South Africa. Whole blood was sampled for RISK11 by quantitative RT-PCR assay from eligible volunteers without HIV, recent previous tuberculosis (ie, <3 years before screening), or comorbidities at screening. RISK11-positive participants were block randomised (1:2; block size 15) to once-weekly, directly-observed, open-label isoniazid and rifapentine for 12 weeks (ie, RISK11 positive and 3HP positive), or no treatment (ie, RISK11 positive and 3HP negative). A subset of eligible RISK11-negative volunteers were randomly assigned to no treatment (ie, RISK11 negative and 3HP negative). Diagnostic discrimination of prevalent tuberculosis was tested in all participants at baseline. Thereafter, prognostic discrimination of incident tuberculosis was tested in the untreated RISK11-positive versus RISK11-negative groups, and treatment efficacy in the 3HP-treated versus untreated RISK11-positive groups, during active surveillance through 15 months. The primary endpoint was microbiologically confirmed pulmonary tuberculosis. The primary outcome measures were risk ratio [RR] for tuberculosis of RISK11-positive to RISK11-negative participants, and treatment efficacy. This trial is registered with ClinicalTrials.gov, NCT02735590. 20 207 volunteers were screened, and 2923 participants were enrolled, including RISK11-positive participants randomly assigned to 3HP (n=375) or no 3HP (n=764), and 1784 RISK11-negative participants. Cumulative probability of prevalent or incident tuberculosis disease was 0·066 (95% CI 0·049 to 0·084) in RISK11-positive (3HP negative) participants and 0·018 (0·011 to 0·025) in RISK11-negative participants (RR 3·69, 95% CI 2·25–6·05) over 15 months. Tuberculosis prevalence was 47 (4·1%) of 1139 versus 14 (0·78%) of 1984 in RISK11-positive compared with RISK11-negative participants, respectively (diagnostic RR 5·13, 95% CI 2·93 to 9·43). Tuberculosis incidence over 15 months was 2·09 (95% CI 0·97 to 3·19) vs 0·80 (0·30 to 1·30) per 100 person years in RISK11-positive (3HP-negative) participants compared with RISK11-negative participants (cumulative incidence ratio 2·6, 95% CI 1·2 to 5·9). Serious adverse events related to 3HP included one hospitalisation for seizures (unintentional isoniazid overdose) and one death of unknown cause (possibly temporally related). Tuberculosis incidence over 15 months was 1·94 (95% CI 0·35 to 3·50) versus 2·09 (95% CI 0·97 to 3·19) per 100 person-years in 3HP-treated RISK11-positive participants compared with untreated RISK11-positive participants (efficacy 7·0%, 95% CI −145 to 65). The RISK11 signature discriminated between individuals with prevalent tuberculosis, or progression to incident tuberculosis, and individuals who remained healthy, but provision of 3HP to signature-positive individuals after exclusion of baseline disease did not reduce progression to tuberculosis over 15 months. Bill and Melinda Gates Foundation, South African Medical Research Council.

Abstract Rationale Global tuberculosis (TB) control requires effective vaccines in TB-endemic countries, where most adults are infected with Mycobacterium tuberculosis (M.tb). Objectives We sought to define optimal dose and schedule of H56:IC31, an experimental TB vaccine comprising Ag85B, ESAT-6, and Rv2660c, for M.tb-infected and M.tb-uninfected adults. Methods We enrolled 98 healthy, HIV-uninfected, bacillus Calmette-Guérin–vaccinated, South African adults. M.tb infection was defined by QuantiFERON-TB (QFT) assay. QFT-negative participants received two vaccinations of different concentrations of H56 in 500 nmol of IC31 to enable dose selection for further vaccine development. Subsequently, QFT-positive and QFT-negative participants were randomized to receive two or three vaccinations to compare potential schedules. Participants were followed for safety and immunogenicity for 292 days. Measurements and Main Results H56:IC31 showed acceptable reactogenicity profiles irrespective of dose, number of vaccinations, or M.tb infection. No vaccine-related severe or serious adverse events were observed. The three H56 concentrations tested induced equivalent frequencies and functional profiles of antigen-specific CD4 T cells. ESAT-6 was only immunogenic in QFT-negative participants who received three vaccinations. Conclusions Two or three H56:IC31 vaccinations at the lowest dose induced durable antigen-specific CD4 T-cell responses with acceptable safety and tolerability profiles in M.tb-infected and M.tb-uninfected adults. Additional studies should validate applicability of vaccine doses and regimens to both QFT-positive and QFT-negative individuals. Clinical trial registered with www.clinicaltrials.gov (NCT01865487).

Development of an effective vaccine against tuberculosis is a critical step towards reducing the global burden of disease. A therapeutic vaccine might also reduce the high rate of TB recurrence and help address the challenges of drug-resistant strains. ID93+GLA-SE is a candidate subunit vaccine that will soon be evaluated in a phase 2b efficacy trial for prevention of recurrent TB among patients undergoing TB treatment. ID93+GLA-SE vaccination was shown to elicit robust CD4+ T cell and IgG antibody responses among recently treated TB patients in the TBVPX-203 Phase 2a study (NCT02465216), but the mechanisms underlying these responses are not well understood. In this study we used specimens from TBVPX-203 participants to describe the changes in peripheral blood gene expression that occur after ID93+GLA-SE vaccination. Analyses revealed several distinct modules of co-varying genes that were either up- or down-regulated after vaccination, including genes associated with innate immune pathways at 3 days post-vaccination and genes associated with lymphocyte expansion and B cell activation at 7 days post-vaccination. Notably, the regulation of these gene modules was affected by the dose schedule and by participant sex, and early innate gene signatures were correlated with the ID93-specific CD4+ T cell response. The results provide insight into the complex interplay of the innate and adaptive arms of the immune system in developing responses to vaccination with ID93+GLA-SE and demonstrate how dosing and schedule can affect vaccine responses.

Background Clinical trials conducted in rural resource-poor settings face special challenges in ensuring quality of data collection and handling. The variable nature of these challenges, ways to overcome them, and the resulting data quality are rarely reported in the literature. Purpose To provide a detailed example of establishing local data handling capacity for a clinical trial conducted in a rural area, highlight challenges and solutions in establishing such capacity, and to report the data quality obtained by the trial. Methods We provide a descriptive case study of a data system for biological samples and questionnaire data, and the problems encountered during its implementation. To determine the quality of data we analyzed test—retest studies using Kappa statistics of inter- and intra-observer agreement on categorical data. We calculated Technical Errors of Measurement of anthropometric measurements, audit trail analysis was done to assess error correction rates, and residual error rates were calculated by database-to-source document comparison. Results Initial difficulties included the unavailability of experienced research nurses, programmers and data managers in this rural area and the difficulty of designing new software tools and a complex database while making them error-free. National and international collaboration and external monitoring helped ensure good data handling and implementation of good clinical practice. Data collection, fieldwork supervision and query handling depended on streamlined transport over large distances. The involvement of a community advisory board was helpful in addressing cultural issues and establishing community acceptability of data collection methods. Data accessibility for safety monitoring required special attention. Kappa values and Technical Errors of Measurement showed acceptable values. Residual error rates in key variables were low. Limitations The article describes the experience of a single-site trial and does not address challenges particular to multi-site trials. Conclusions Obtaining and maintaining data integrity in rural clinical trials is feasible, can result in acceptable data quality and can be used to develop capacity in developing country sites. It does, however, involve special challenges and requirements. Clinical Trials 2007; 4: 572—582. http://ctj.sagepub.com

Diagnosis of childhood tuberculosis is limited by the paucibacillary respiratory samples obtained from young children with pulmonary disease. We aimed to compare accuracy of the Xpert® MTB/RIF assay, an automated nucleic acid amplification test, between induced sputum and gastric lavage samples from young children in a tuberculosis endemic setting. We analyzed standardized diagnostic data from HIV negative children younger than four years of age who were investigated for tuberculosis disease near Cape Town, South Africa [2009-2012]. Two paired, consecutive induced sputa and early morning gastric lavage samples were obtained from children with suspected tuberculosis. Samples underwent Mycobacterial Growth Indicator Tube [MGIT] culture and Xpert MTB/RIF assay. We compared diagnostic yield across samples using the two-sample test of proportions and McNemar's χ2 test; and Wilson's score method to calculate sensitivity and specificity. 1,020 children were evaluated for tuberculosis during 1,214 admission episodes. Not all children had 4 samples collected. 57 of 4,463[1.3%] and 26 of 4,606[0.6%] samples tested positive for Mycobacterium tuberculosis on MGIT culture and Xpert MTB/RIF assay respectively. 27 of 2,198[1.2%] and 40 of 2,183[1.8%] samples tested positive [on either Xpert MTB/RIF assay or MGIT culture] on induced sputum and gastric lavage samples, respectively. 19/1,028[1.8%] and 33/1,017[3.2%] admission episodes yielded a positive MGIT culture or Xpert MTB/RIF assay from induced sputum and gastric lavage, respectively. Sensitivity of Xpert MTB/RIF assay was 8/30[26.7%; 95% CI: 14.2-44.4] for two induced sputum samples and 7/31[22.6%; 11.4-39.8] [p = 0.711] for two gastric lavage samples. Corresponding specificity was 893/893[100%;99.6-100] and 885/890[99.4%;98.7-99.8] respectively [p = 0.025]. Sensitivity of Xpert MTB/RIF assay was low, compared to MGIT culture, but diagnostic performance of Xpert MTB/RIF did not differ sufficiently between induced sputum and gastric lavage to justify selection of one sampling method over the other, in young children with suspected pulmonary TB. ClinicalTrials.gov NCT00953927.

Background Vaccination that prevents tuberculosis (TB) disease, particularly in adolescents, would have the greatest impact on the global TB epidemic. Safety, reactogenicity and immunogenicity of the vaccine candidate M72/AS01Ewas evaluated in healthy, HIV-negative adolescents in a TB endemic region, regardless ofMycobacterium tuberculosis(M.tb) infection status. Methods In a phase II, double-blind randomized, controlled study (NCT00950612), two doses of M72/AS01Eor placebo were administered intramuscularly, one month apart. Participants were followed-up post-vaccination, for 6 months. M72-specific immunogenicity was evaluated by intracellular cytokine staining analysis of T cells and NK cells by flow cytometry. Results No serious adverse events were recorded. M72/AS01Einduced robust T cell and antibody responses, including antigen-dependent NK cell IFN-γ production. CD4 and CD8 T cell responses were sustained at 6 months post vaccination. Irrespective ofM.tbinfection status, vaccination induced a high frequency of M72-specific CD4 T cells expressing multiple combinations of Th1 cytokines, and low level IL-17. We observed rapid boosting of immune responses inM.tb-infected participants, suggesting natural infection acts as a prime to vaccination. Conclusions The clinically acceptable safety and immunogenicity profile of M72/AS01Ein adolescents living in an area with high TB burden support the move to efficacy trials.