• HBV-RNA Co-amplification May Influence HBV DNA Viral Load Determination.

      Maasoumy, Benjamin; Geretti, Anna Maria; Frontzek, André; Austin, Harrison; Aretzweiler, Gudrun; Garcia-Álvarez, Monica; Leuchter, Susanne; Simon, Christian O; Marins, Ed G; Canchola, Jesse A; et al. (Wiley, 2020-05-26)
      Despite effective hepatitis B virus (HBV)-DNA suppression, HBV RNA can circulate in patients receiving nucleoside/nucleotide analogues (NAs). Current assays quantify HBV DNA by either real-time polymerase chain reaction (PCR), which uses DNA polymerase, or transcription-mediated amplification, which uses reverse-transcriptase (RT) and RNA polymerase. We assessed the effect of RT capability on HBV-DNA quantification in samples from three cohorts, including patients with quantified HBV RNA. We compared the HBV-DNA levels by real-time PCR (cobas HBV, Roche 6800/8800; Xpert HBV, Cepheid), transcription-mediated amplification (Aptima HBV, Hologic), and real-time PCR with added RT capability (cobas HBV+RT). In the first cohort (n = 45) followed over 192 weeks of NA therapy, on-treatment HBV-DNA levels were higher with cobas HBV+RT than cobas HBV (mean difference: 0.14 log10 IU/mL). In a second cohort (n = 50) followed over 96 weeks of NA therapy, HBV-DNA viral load was significantly higher with the cobas HBV+RT and Aptima HBV compared with the cobas HBV test at all time points after initiation of NA therapy (mean difference: 0.65-1.16 log10 IU/mL). A clinically significant difference was not detected between the assays at baseline. In a third cohort (n = 53), after a median of 2.2 years of NA therapy, we detected HBV RNA (median 5.6 log10 copies/mL) in 23 patients (43.4%). Median HBV-DNA levels by Aptima HBV were 2.4 versus less than 1 log10 IU/mL in samples with HBV RNA and without HBV RNA, respectively (P = 0.0006). In treated patients with HBV RNA, Aptima HBV measured higher HBV-DNA levels than Xpert HBV and cobas HBV. Conclusion: Tests including an RT step may overestimate HBV DNA, particularly in samples with low viral loads as a result of NA therapy. This overestimation is likely due to amplification of HBV RNA and may have an impact on clinical decisions.
    • Cellular and humoral immunogenicity of a SARS-CoV-2 mRNA vaccine in patients on haemodialysis.

      Strengert, Monika; Becker, Matthias; Ramos, Gema Morillas; Dulovic, Alex; Gruber, Jens; Juengling, Jennifer; Lürken, Karsten; Beigel, Andrea; Wrenger, Eike; Lonnemann, Gerhard; et al. (Elsevier, 2021-08-12)
      Background: Patients with chronic renal insufficiency on maintenance haemodialysis face an increased risk of COVID-19 induced mortality and impaired vaccine responses. To date, only a few studies have addressed SARS-CoV-2 vaccine elicited immunity in this immunocompromised population. Methods: We assessed immunogenicity of the mRNA vaccine BNT162b2 in at-risk dialysis patients and characterised systemic cellular and humoral immune responses in serum and saliva using interferon γ release assay and multiplex-based cytokine and immunoglobulin measurements. We further compared binding capacity and neutralization efficacy of vaccination-induced immunoglobulins against emerging SARS-CoV-2 variants Alpha, Beta, Epsilon and Cluster 5 by ACE2-RBD competition assay. Findings: Patients on maintenance haemodialysis exhibit detectable but variable cellular and humoral immune responses against SARS-CoV-2 and variants of concern after a two-dose regimen of BNT162b2. Although vaccination-induced immunoglobulins were detectable in saliva and plasma, both anti-SARS-CoV-2 IgG and neutralization efficacy was reduced compared to a vaccinated non-dialysed control population. Similarly, T-cell mediated interferon γ release after stimulation with SARS-CoV-2 spike peptides was significantly diminished. Interpretation: Quantifiable humoral and cellular immune responses after BNT162b2 vaccination in individuals on maintenance haemodialysis are encouraging, but urge for longitudinal follow-up to assess longevity of immunity. Diminished virus neutralization and interferon γ responses in the face of emerging variants of concern may favour this at-risk population for re-vaccination using modified vaccines at the earliest opportunity. Funding: Initiative and Networking Fund of the Helmholtz Association of German Research Centres, EU Horizon 2020 research and innovation program, State Ministry of Baden-Württemberg for Economic Affairs, Labour and Tourism.
    • The role of sirtuin 1 on the induction of trained immunity.

      Mourits, Vera P; Helder, Leonie S; Matzaraki, Vasiliki; Koeken, Valerie A C M; Groh, Laszlo; de Bree, L Charlotte J; Moorlag, Simone J C F M; van der Heijden, Charlotte D C C; Keating, Samuel T; van Puffelen, Jelmer H; et al. (Elsevier, 2021-06-12)
      Sirtuin 1 (SIRT1) has been described to modify immune responses by modulation of gene transcription. As transcriptional reprogramming is the molecular substrate of trained immunity, a de facto innate immune memory, we investigated the role of SIRT1 in the induction of trained immunity. We identified various SIRT1 genetic single nucleotide polymorphisms affecting innate and adaptive cytokine production of human peripheral blood mononuclear cells (PBMCs) in response to various stimuli on the one hand, and in vitro induction of trained immunity on the other hand. Furthermore, inhibition of SIRT1 upregulated pro-inflammatory innate cytokine production upon stimulation of PBMCs. However, inhibition of SIRT1 in vitro had no effect on cytokine responses upon induction of trained immunity, while activation of SIRT1 mildly modified trained immunity responses. In conclusion, SIRT1 modifies innate cytokine production by PBMCs in response to various microbes, but has only a secondary role for BCG and β-glucan-induced trained immunity responses.
    • Antimicrobial resistance in patients with decompensated liver cirrhosis and bacterial infections in a tertiary center in Northern Germany.

      Hillert, Annika; Schultalbers, Marie; Tergast, Tammo L; Vonberg, Ralf-Peter; Rademacher, Jessica; Wedemeyer, Heiner; Cornberg, Markus; Ziesing, Stefan; Maasoumy, Benjamin; Höner Zu Siederdissen, Christoph; et al. (BMC, 2021-07-20)
      Background and aims: Bacterial infections are common in patients with decompensated liver cirrhosis and a leading cause of death. Reliable data on antibiotic resistance are required to initiate effective empiric therapy. We here aim to assess the antimicrobial resistance profile of bacteria among patients with liver cirrhosis and infection. Methods: Overall, 666 cirrhotic patients admitted to Hannover Medical School between January 2012 and April 2018 with ascites were assessed for bacterial infection. In case of infection, bacteria cultured from microbiological specimens of ascites, blood or urine were identified and analyzed for resistances against common antibiotic agents. Furthermore, analyses compared two periods of time and community-acquired vs. nosocomial infections. Results: In 281 patients with infection, microbiological sampling was performed and culture-positive results were obtained in 56.9%. Multidrug-resistant (MDR)-bacteria were found in 54 patients (19.2%). Gram-positive organisms were more common (n = 141/261, 54.0%) and detected in 116/192 culture-positive infections (60.4%). Comparing infections before and after 2015, a numerical decline for MDR-bacteria (23.8% vs. 15.6%, p = 0.08) was observed with a significant decline in meropenem resistance (34.9% vs. 19.5%, p = 0.03). MDR-bacteria were more frequent in the case of nosocomial infections. Of note, in ascites the majority of the tested bacteria were resistant against ceftriaxone (73.8%) whereas significantly less were resistant against meropenem (27.0%) and vancomycin (25.9%). Conclusions: In our tertiary center, distinct ratios of gram-positive infection with overall low ratios of MDR-bacteria were found. Adequate gram-positive coverage in the empiric therapy should be considered. Carbapenem treatment may be omitted even in nosocomial infection. In contrast, 3rd generation cephalosporins cannot be recommended even in community-acquired infection in our cirrhotic population.
    • Controlling inflammation in the elderly with BCG vaccination.

      Koeken, Valerie A C M; CiiM, Zentrum für individualisierte Infektionsmedizin, Feodor-Lynen-Str.7, 30625 Hannover. (AAAS, 2021-08-04)
      The tuberculosis vaccine BCG may protect against inflammation in the elderly as well as offer an option for protection from SARS-CoV-2 in developing countries.
    • Reaching the Unreachable: Strategies for HCV Eradication in Patients With Refractory Opioid Addiction-A Real-world Experience.

      Sandmann, Lisa; Deppe, Julian; Beier, Christoph; Ohlendorf, Valerie; Schneider, Julia; Wedemeyer, Heiner; Wedegärtner, Felix; Cornberg, Markus; Maasoumy, Benjamin; CiiM, Zentrum für individualisierte Infektionsmedizin, Feodor-Lynen-Str.7, 30625 Hannover. (2021-06-17)
    • S3-Leitlinie der Deutschen Gesellschaft für Gastroenterologie, Verdauungs- und Stoffwechselkrankheiten (DGVS) zur Prophylaxe, Diagnostik und Therapie der Hepatitis-B-Virusinfektion – (AWMF-Register-Nr. 021-11)

      Cornberg, Markus; Sandmann, Lisa; Protzer, Ulrike; Niederau, Claus; Tacke, Frank; Berg, Thomas; Glebe, Dieter; Jilg, Wolfgang; Wedemeyer, Heiner; Wirth, Stefan; et al. (Thieme, 2021-07-12)
      [No abstract available]
    • Leitlinienreport zur aktualisierten S3-Leitlinie der Deutschen Gesellschaft für Gastroenterologie, Verdauungs- und Stoffwechselkrankheiten (DGVS) zur Prophylaxe, Diagnostik und Therapie der Hepatitis-B-Virusinfektion

      Jansen, Petra Lynen; van Leeuwen, Pia; Sandmann, Lisa; Cornberg, Markus; CiiM, Zentrum für individualisierte Infektionsmedizin, Feodor-Lynen-Str.7, 30625 Hannover. (Thieme, 2021-07-12)
      [No abstract available]
    • Integration of metabolomics, genomics, and immune phenotypes reveals the causal roles of metabolites in disease.

      Chu, Xiaojing; Jaeger, Martin; Beumer, Joep; Bakker, Olivier B; Aguirre-Gamboa, Raul; Oosting, Marije; Smeekens, Sanne P; Moorlag, Simone; Mourits, Vera P; Koeken, Valerie A C M; et al. (BMC, 2021-07-06)
      Background: Recent studies highlight the role of metabolites in immune diseases, but it remains unknown how much of this effect is driven by genetic and non-genetic host factors. Result: We systematically investigate circulating metabolites in a cohort of 500 healthy subjects (500FG) in whom immune function and activity are deeply measured and whose genetics are profiled. Our data reveal that several major metabolic pathways, including the alanine/glutamate pathway and the arachidonic acid pathway, have a strong impact on cytokine production in response to ex vivo stimulation. We also examine the genetic regulation of metabolites associated with immune phenotypes through genome-wide association analysis and identify 29 significant loci, including eight novel independent loci. Of these, one locus (rs174584-FADS2) associated with arachidonic acid metabolism is causally associated with Crohn's disease, suggesting it is a potential therapeutic target. Conclusion: This study provides a comprehensive map of the integration between the blood metabolome and immune phenotypes, reveals novel genetic factors that regulate blood metabolite concentrations, and proposes an integrative approach for identifying new disease treatment targets.
    • Significant compartment-specific impact of different RNA extraction methods and PCR assays on the sensitivity of hepatitis E virus detection.

      Behrendt, Patrick; Bremer, Birgit; Todt, Daniel; Steinmann, Eike; Manns, Michael Peter; Cornberg, Markus; Wedemeyer, Heiner; Maasoumy, Benjamin; CiiM, Zentrum für individualisierte Infektionsmedizin, Feodor-Lynen-Str.7, 30625 Hannover. (Wiley, 2021-03-22)
      We determined the limit of detection of the RealStar HEV RT-PCR V2.0 Kit (altona Diagnostics, RS) utilizing 3 RNA extraction methods (COBAS® AmpliPrep Total Nucleic Acid Isolation Kit, TNAi Roche; MagNA Pure 96 DNA, Viral NA SV Kit, MgP; QIAamp Viral RNA mini Kit Qiagen; VRK) in plasma and stool. The most sensitive method was evaluated in a total of 307 longitudinal samples of patients with HEV infection (acute = 18/chronic = 36) and compared to results with the former diagnostic standard of our centre (TNAi/FastTrack Diagnostic; FTD).
    • Multi-Omics Approaches in Immunological Research.

      Chu, Xiaojing; Zhang, Bowen; Koeken, Valerie A C M; Gupta, Manoj Kumar; Li, Yang; CiiM, Zentrum für individualisierte Infektionsmedizin, Feodor-Lynen-Str.7, 30625 Hannover. (2021-06-11)
      The immune system plays a vital role in health and disease, and is regulated through a complex interactive network of many different immune cells and mediators. To understand the complexity of the immune system, we propose to apply a multi-omics approach in immunological research. This review provides a complete overview of available methodological approaches for the different omics data layers relevant for immunological research, including genetics, epigenetics, transcriptomics, proteomics, metabolomics, and cellomics. Thereafter, we describe the various methods for data analysis as well as how to integrate different layers of omics data. Finally, we discuss the possible applications of multi-omics studies and opportunities they provide for understanding the complex regulatory networks as well as immune variation in various immune-related diseases.
    • Distinct Immune Imprints of Post-Liver Transplantation Hepatitis C Persist Despite Viral Clearance.

      Aregay, Amare; Engel, Bastian; Port, Kerstin; Vondran, Florian W R; Bremer, Birgit; Niehaus, Christian; Khera, Tanvi; Richter, Nicolas; Jaeckel, Elmar; Cornberg, Markus; et al. (Wiley, 2021-02-28)
      Recurrence or de novo infection of hepatitis C virus (HCV) after liver transplantation (LT) has been associated with progressive graft hepatitis that can be improved by treatment with novel direct-acting antivirals. Cases of rejection episodes have been described during and after HCV treatment. The evolution of innate and adaptive immune response during and after cure of HCV LT is unknown. We studied 74 protein biomarkers in the plasma of LT patients receiving antiviral therapy. In addition, deep immune phenotyping of both the myeloid and lymphoid immune cell subsets in peripheral blood mononuclear cells was performed. We found that LT patients with active HCV infection displayed distinct alterations of inflammatory protein biomarkers, such as C-X-Cmotif chemokine 10 (CXCL10), caspase 8, C-C motif chemokine 20 (CCL20), CCL19, interferon γ, CUB domain-containing protein 1 (CDCP1), interleukin (IL)-18R1, CXCL11, CCL3, IL8, IL12B, tumor necrosis factor-beta, CXCL6, osteoprotegerin, IL10, fms-related tyrosine kinase 3 ligand, hepatocyte growth factor, urokinase-type plasminogen activator, neurotrophin-3, CCL4, IL6, tumornecrosis factor receptor superfamily member 9, programmed death ligand 1, IL18, and monocyte chemotactic protein 1, and enrichment of peripheral immune cell subsets unlike patients without HCV infection who received transplants. Interestingly, patients who cleared HCV after LT did not normalize the altered inflammatory milieu nor did the peripheral immune cell subsets normalize to what would be seen in the absence of HCV recurrence. Overall, these data indicate that HCV-specific imprints on inflammatory analytes and immune cell subsets after LT are not completely normalized by therapy-induced HCV elimination. This is in line with the clinical observation that cure of HCV after LT did not trigger rejection episodes in many patients.
    • Protected or not protected, that is the question - First data on COVID-19 vaccine responses in patients with NAFLD and liver transplant recipients.

      Eberhardt, Christiane S; Cornberg, Markus; CiiM, Zentrum für individualisierte Infektionsmedizin, Feodor-Lynen-Str.7, 30625 Hannover. (2021-05-25)
      [no abstract available]
    • S1 guideline for the care of liver transplant recipients during the COVID-19 pandemic. AWMF Registry No. 021-031 - Status: January 7, 2021

      Tacke, Frank; Cornberg, Markus; Sterneck, Martina; Trebicka, Jonel; Settmacher, Utz; Bechstein, Wolf Otto; Berg, Thomas; CiiM, Zentrum für individualisierte Infektionsmedizin, Feodor-Lynen-Str.7, 30625 Hannover. (Thieme, 2021-04-01)
      [No abstract listed]
    • Glutathione Metabolism Contributes to the Induction of Trained Immunity.

      Ferreira, Anaisa V; Koeken, Valerie A C M; Matzaraki, Vasiliki; Kostidis, Sarantos; Alarcon-Barrera, Juan Carlos; de Bree, L Charlotte J; Moorlag, Simone J C F M; Mourits, Vera P; Novakovic, Boris; Giera, Martin A; et al. (MDPI, 2021-04-21)
      The innate immune system displays heterologous memory characteristics, which are characterized by stronger responses to a secondary challenge. This phenomenon termed trained immunity relies on epigenetic and metabolic rewiring of innate immune cells. As reactive oxygen species (ROS) production has been associated with the trained immunity phenotype, we hypothesized that the increased ROS levels and the main intracellular redox molecule glutathione play a role in the induction of trained immunity. Here we show that pharmacological inhibition of ROS in an in vitro model of trained immunity did not influence cell responsiveness; the modulation of glutathione levels reduced pro-inflammatory cytokine production in human monocytes. Single nucleotide polymorphisms (SNPs) in genes involved in glutathione metabolism were found to be associated with changes in pro-inflammatory cytokine production capacity upon trained immunity. Also, plasma glutathione concentrations were positively associated with ex vivo IL-1β production, a biomarker of trained immunity, produced by monocytes of BCG-vaccinated individuals. In conclusion, glutathione metabolism is involved in the induction of trained immunity, and future studies are warranted to explore its functional consequences in human diseases.
    • Experimental Drugs for the Treatment of Hepatitis D.

      Sandmann, Lisa; Cornberg, Markus; CiiM, Zentrum für individualisierte Infektionsmedizin, Feodor-Lynen-Str.7, 30625 Hannover. (Dovepress, 2021-04-16)
      Chronic hepatitis D virus infection is the most severe form of viral hepatitis. Antiviral treatment is urgently needed to prevent patients from developing end stage liver disease or hepatocellular carcinoma. Treatment options were limited to off-label use of pegylated interferon alfa until conditional approval of bulevirtide by the EMA (European Medicines Agency) in July 2020. However, several other antiviral compounds are currently investigated and represent promising agents for the treatment of chronic HDV infection.
    • Residential PM exposure and the nasal methylome in children.

      Sordillo, Joanne E; Cardenas, Andres; Qi, Cancan; Rifas-Shiman, Sheryl L; Coull, Brent; Luttmann-Gibson, Heike; Schwartz, Joel; Kloog, Itai; Hivert, Marie-France; DeMeo, Dawn L; et al. (Elsevier, 2021-04-16)
      Rationale: PM2.5-induced adverse effects on respiratory health may be driven by epigenetic modifications in airway cells. The potential impact of exposure duration on epigenetic alterations in the airways is not yet known. Objectives: We aimed to study associations of fine particulate matter PM2.5 exposure with DNA methylation in nasal cells. Methods: We conducted nasal epigenome-wide association analyses within 503 children from Project Viva (mean age 12.9 y), and examined various exposure durations (1-day, 1-week, 1-month, 3-months and 1-year) prior to nasal sampling. We used residential addresses to estimate average daily PM2.5 at 1 km resolution. We collected nasal swabs from the anterior nares and measured DNA methylation (DNAm) using the Illumina MethylationEPIC BeadChip. We tested 719,075 high quality autosomal CpGs using CpG-by-CpG and regional DNAm analyses controlling for multiple comparisons, and adjusted for maternal education, household smokers, child sex, race/ethnicity, BMI z-score, age, season at sample collection and cell-type heterogeneity. We further corrected for bias and genomic inflation. We tested for replication in a cohort from the Netherlands (PIAMA). Results: In adjusted analyses, we found 362 CpGs associated with 1-year PM2.5 (FDR < 0.05), 20 CpGs passing Bonferroni correction (P < 7.0x10-8) and 10 Differentially Methylated Regions (DMRs). In 445 PIAMA participants (mean age 16.3 years) 11 of 203 available CpGs replicated at P < 0.05. We observed differential DNAm at/near genes implicated in cell cycle, immune and inflammatory responses. There were no CpGs or regions associated with PM2.5 levels at 1-day, 1-week, or 1-month prior to sample collection, although 2 CpGs were associated with past 3-month PM2.5. Conclusion: We observed wide-spread DNAm variability associated with average past year PM2.5 exposure but we did not detect associations with shorter-term exposure. Our results suggest that nasal DNAm marks reflect chronic air pollution exposure.
    • The impact of hepatitis B surface antigen on natural killer cells in patients with chronic hepatitis B virus infection.

      Du, Yanqin; Anastasiou, Olympia E; Strunz, Benedikt; Scheuten, Janina; Bremer, Birgit; Kraft, Anke; Kleinsimglinhaus, Karolina; Todt, Daniel; Broering, Ruth; Hardtke-Wolenski, Matthias; et al. (Wiley, 2021-04-01)
      Compared to the healthy controls, a reshaping of NK cell pool towards more CD56bright NK cells was observed during CHB infection. Importantly, NK cells in patients with low HBsAg levels (<100 IU/mL) displayed an activated phenotype with increased expression of activation makers CD38, granzyme B and proliferation marker Ki-67 while presenting with defective functional responses (MIP-1β, CD107a) at the same time. Furthermore, NK cell activation was negatively correlated with patient HBsAg levels while NK function correlated with patient age.
    • Polymorphisms within Autophagy-Related Genes Influence the Risk of Developing Colorectal Cancer: A Meta-Analysis of Four Large Cohorts.

      Sainz, Juan; García-Verdejo, Francisco José; Martínez-Bueno, Manuel; Kumar, Abhishek; Sánchez-Maldonado, José Manuel; Díez-Villanueva, Anna; Vodičková, Ludmila; Vymetálková, Veronika; Martin Sánchez, Vicente; Da Silva Filho, Miguel Inacio; et al. (MDPI, 2021-03-12)
      The role of genetic variation in autophagy-related genes in modulating autophagy and cancer is poorly understood. Here, we comprehensively investigated the association of autophagy-related variants with colorectal cancer (CRC) risk and provide new insights about the molecular mechanisms underlying the associations. After meta-analysis of the genome-wide association study (GWAS) data from four independent European cohorts (8006 CRC cases and 7070 controls), two loci, DAPK2 (p = 2.19 × 10-5) and ATG5 (p = 6.28 × 10-4) were associated with the risk of CRC. Mechanistically, the DAPK2rs11631973G allele was associated with IL1 β levels after the stimulation of peripheral blood mononuclear cells (PBMCs) with Staphylococcus aureus (p = 0.002), CD24 + CD38 + CD27 + IgM + B cell levels in blood (p = 0.0038) and serum levels of en-RAGE (p = 0.0068). ATG5rs546456T allele was associated with TNF α and IL1 β levels after the stimulation of PBMCs with LPS (p = 0.0088 and p = 0.0076, respectively), CD14+CD16- cell levels in blood (p = 0.0068) and serum levels of CCL19 and cortisol (p = 0.0052 and p = 0.0074, respectively). Interestingly, no association with autophagy flux was observed. These results suggested an effect of the DAPK2 and ATG5 loci in the pathogenesis of CRC, likely through the modulation of host immune responses.
    • BCG-induced protection against Mycobacterium tuberculosis infection: Evidence, mechanisms, and implications for next-generation vaccines.

      Foster, Mitchell; Hill, Philip C; Setiabudiawan, Todia Pediatama; Koeken, Valerie A C M; Alisjahbana, Bachti; van Crevel, Reinout; CiiM, Zentrum für individualisierte Infektionsmedizin, Feodor-Lynen-Str.7, 30625 Hannover. (2021-03-12)
      The tuberculosis (TB) vaccine Bacillus Calmette-Guérin (BCG) was introduced 100 years ago, but as it provides insufficient protection against TB disease, especially in adults, new vaccines are being developed and evaluated. The discovery that BCG protects humans from becoming infected with Mycobacterium tuberculosis (Mtb) and not just from progressing to TB disease provides justification for considering Mtb infection as an endpoint in vaccine trials. Such trials would require fewer participants than those with disease as an endpoint. In this review, we first define Mtb infection and disease phenotypes that can be used for mechanistic studies and/or endpoints for vaccine trials. Secondly, we review the evidence for BCG-induced protection against Mtb infection from observational and BCG re-vaccination studies, and discuss limitations and variation of this protection. Thirdly, we review possible underlying mechanisms for BCG efficacy against Mtb infection, including alternative T cell responses, antibody-mediated protection, and innate immune mechanisms, with a specific focus on BCG-induced trained immunity, which involves epigenetic and metabolic reprogramming of innate immune cells. Finally, we discuss the implications for further studies of BCG efficacy against Mtb infection, including for mechanistic research, and their relevance to the design and evaluation of new TB vaccines.