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Abstract Lassa virus (LASV) is a rodent-borne mammarenavirus that causes tens to hundreds of thousands of human infections annually in Western Africa. Approximately 20% of these infections progress to Lassa fever (LF), an acute disease with case–fatality rates from ≈20–70%. Currently, there are no approved vaccines or specific therapeutics to prevent or treat LF. The LASV genome consists of a small (S) segment that has two genes, GP and NP, and a large (L) segment that has two genes, L and Z. In both segments, the two genes are separated by non-coding intergenic regions (IGRs). Recombinant LASVs (rLASVs), in which the L segment IGR was replaced with the S segment IGR or in which the GP gene was codon-deoptimized, lost fitness in vitro, were highly attenuated in vivo, and, when used as vaccines, protected domesticated guinea pigs from otherwise lethal LASV exposure. Here, we report the generation of rLASV/IGR-CD, which includes both determinants of attenuation and further enhances the safety of the vaccine compared with its predecessors. rLASV/IGR-CD grew to high titers in Vero cells, which are approved for human vaccine production, but did not cause signs of disease or pathology in guinea pigs. Importantly, guinea pigs vaccinated with rLASV/IGR-CD were completely protected from disease and death after a typically lethal exposure to wild-type LASV. Our data support the development of rLASV/IGR-CD as a live-attenuated LF vaccine with stringent safety features.

Abstract Detection of the physiological response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is challenging in the absence of overt clinical signs but remains necessary to understand a full subclinical disease spectrum. In this study, our objective was to use radiomics (from computed tomography images) and blood biomarkers to predict SARS-CoV-2 infection in a nonhuman primate model (NHP) with inapparent clinical disease. To accomplish this aim, we built machine-learning models to predict SARS-CoV-2 infection in a NHP model of subclinical disease using baseline-normalized radiomic and blood sample analyses data from SARS-CoV-2-exposed and control (mock-exposed) crab-eating macaques. We applied a novel adaptation of the minimum redundancy maximum relevance (mRMR) feature-selection technique, called mRMR-permute, for statistically-thresholded and unbiased feature selection. Through performance comparison of eight machine-learning models trained on 14 feature sets, we demonstrated that a logistic regression model trained on the mRMR-permute feature set can predict SARS-CoV-2 infection with very high accuracy. Eighty-nine percent of mRMR-permute selected features had strong and significant class effects. Through this work, we identified a key set of radiomic and blood biomarkers that can be used to predict infection status even in the absence of clinical signs. Furthermore, we proposed and demonstrated the utility of a novel feature-selection technique called mRMR-permute. This work lays the foundation for the prediction and classification of SARS-CoV-2 disease severity.

Deep characterization of uveitis in a rhesus monkey confirms Ebola virus RNA persistence is associated with severe immunopathology in the eye, with broader implications for the prevention and treatment of sight-threatening uveitis in human survivors of Ebola virus.

ABSTRACT Marburg virus (MARV) is a highly virulent zoonotic filovirid that causes Marburg virus disease (MVD) in humans. The pathogenesis of MVD remains poorly understood, partially due to the low number of cases that can be studied, the absence of state-of-the-art medical equipment in areas where cases are reported, and limitations on the number of animals that can be safely used in experimental studies under maximum containment animal biosafety level 4 conditions. Medical imaging modalities, such as whole-body computed tomography (CT), may help to describe disease progression in vivo, potentially replacing ethically contentious and logistically challenging serial euthanasia studies. Towards this vision, we performed a pilot study, during which we acquired whole-body CT images of 6 rhesus monkeys before and 7 to 9 days after intramuscular MARV exposure. We identified imaging abnormalities in the liver, spleen, and axillary lymph nodes that corresponded to clinical, virological, and gross pathological hallmarks of MVD in this animal model. Quantitative image analysis indicated hepatomegaly with a significant reduction in organ density (indicating fatty infiltration of the liver), splenomegaly, and edema that corresponded with gross pathological and histopathological findings. Our results indicated that CT imaging could be used to verify and quantify typical MVD pathogenesis versus altered, diminished, or absent disease severity or progression in the presence of candidate medical countermeasures, thus possibly reducing the number of animals needed and eliminating serial euthanasia. IMPORTANCE Marburg virus (MARV) is a highly virulent zoonotic filovirid that causes Marburg virus disease (MVD) in humans. Much is unknown about disease progression and, thus, prevention and treatment options are limited. Medical imaging modalities, such as whole-body computed tomography (CT), have the potential to improve understanding of MVD pathogenesis. Our study used CT to identify abnormalities in the liver, spleen, and axillary lymph nodes that corresponded to known clinical signs of MVD in this animal model. Our results indicated that CT imaging and analyses could be used to elucidate pathogenesis and possibly assess the efficacy of candidate treatments.

Abstract The recent emergence of multiple SARS‐CoV‐2 variants has caused considerable concern due to both reduced vaccine efficacy and escape from neutralizing antibody therapeutics. It is, therefore, paramount to develop therapeutic strategies that inhibit all known and future SARS‐CoV‐2 variants. Here, we report that all SARS‐CoV‐2 variants analyzed, including variants of concern (VOC) Alpha, Beta, Gamma, Delta, and Omicron, exhibit enhanced binding affinity to clinical grade and phase 2 tested recombinant human soluble ACE2 (APN01). Importantly, soluble ACE2 neutralized infection of VeroE6 cells and human lung epithelial cells by all current VOC strains with markedly enhanced potency when compared to reference SARS‐CoV‐2 isolates. Effective inhibition of infections with SARS‐CoV‐2 variants was validated and confirmed in two independent laboratories. These data show that SARS‐CoV‐2 variants that have emerged around the world, including current VOC and several variants of interest, can be inhibited by soluble ACE2, providing proof of principle of a pan‐SARS‐CoV‐2 therapeutic.

A 46-year-old patient with previously documented Ebola virus persistence in his ocular fluid, associated with severe panuveitis, developed a visually significant cataract. A multidisciplinary approach was taken to prevent and control infection. Ebola virus persistence was assessed before and during the operation to provide safe, vision-restorative phacoemulsification surgery.

Ebola virus (EBOV) can persist in immunologically protected body sites in survivors of Ebola virus disease, creating the potential to initiate new chains of transmission. From the outbreak in West Africa during 2014–2016, we identified 13 possible events of viral persistence–derived transmission of EBOV (VPDTe) and applied predefined criteria to classify transmission events based on the strength of evidence for VPDTe and source and route of transmission. For 8 events, a recipient case was identified; possible source cases were identified for 5 of these 8. For 5 events, a recipient case or chain of transmission could not be confidently determined. Five events met our criteria for sexual transmission (male-to-female). One VPDTe event led to at least 4 generations of cases; transmission was limited after the other events. VPDTe has increased the importance of Ebola survivor services and sustained surveillance and response capacity in regions with previously widespread transmission.

The Ebola virus disease outbreak that occurred in Western Africa from 2013–2016, and subsequent smaller but increasingly frequent outbreaks of Ebola virus disease in recent years, spurred an unprecedented effort to develop and deploy effective vaccines, therapeutics, and diagnostics. This effort led to the U.S. regulatory approval of a diagnostic test, two vaccines, and two therapeutics for Ebola virus disease indications. Moreover, the establishment of fieldable diagnostic tests improved the speed with which patients can be diagnosed and public health resources mobilized. The United States government has played and continues to play a key role in funding and coordinating these medical countermeasure efforts. Here, we describe the coordinated U.S. government response to develop medical countermeasures for Ebola virus disease and we identify lessons learned that may improve future efforts to develop and deploy effective countermeasures against other filoviruses, such as Sudan virus and Marburg virus.

BackgroundFollowing the West African Ebola virus disease (EVD) outbreak of 2013-2016 and more recent EVD outbreaks in the Democratic Republic of Congo, thousands of EVD survivors are at-risk for sequelae including uveitis, which can lead to unremitting inflammation and vision loss from cataract. Because of the known risk of Ebola virus persistence in ocular fluid and the need to provide vision-restorative, safe cataract surgery, the Ebola Virus Persistence in Ocular Tissues and Fluids (EVICT) Study was implemented in Sierra Leone. During implementation of this multi-national study, challenges included regulatory approvals, mobilization, community engagement, infection prevention and control, and collaboration between multiple disciplines. In this report, we address the multifacted approach to address these challenges and the impact of implementation science research to address an urgent clinical subspecialty need in an outbreak setting.Methodology/principal findingsGiven the patient care need to develop a protocol to evaluate ocular fluid for Ebola virus RNA persistence prior to cataract surgery, as well as protocols to provide reassurance to ophthalmologists caring for EVD survivors with cataracts, the EVICT study was designed and implemented through the work of the Ministry of Health, Sierra Leone National Eye Programme, and international partnerships. The EVICT study showed that all 50 patients who underwent ocular fluid sampling at 19 and 34 months, respectively, tested negative for Ebola virus RNA. Thirty-four patients underwent successful cataract surgery with visual acuity improvement. Here we describe the methodology for study implementation, challenges encountered, and key issues that impacted EVD vision care in the immediate aftermath of the EVD outbreak. Key aspects of the EVICT study included defining the pertinent questions and clinical need, partnership alignment with key stakeholders, community engagement with EVD survivor associations, in-country and international regulatory approvals, study site design for infection prevention and control, and thorough plans for EVD survivor follow-up care and monitoring. Challenges encountered included patient mobilization owing to transportation routes and distance of patients in rural districts. Strong in-country partnerships and multiple international organizations overcame these challenges so that lessons learned could be applied for future EVD outbreaks in West and Central Africa including EVD outbreaks that are ongoing in Guinea and Democratic Republic of Congo.Conclusions/significanceThe EVICT Study showed that cataract surgery with a protocol-driven approach was safe and vision-restorative for EVD survivors, which provided guidance for EVD ophthalmic surgical care. Ophthalmologic care remains a key aspect of the public health response for EVD outbreaks but requires a meticulous, yet partnered approach with international and local in-country partners. Future efforts may build on this framework for clinical care and to improve our understanding of ophthalmic sequelae, develop treatment paradigms for EVD survivors, and strengthen vision health systems in resource-limited settings.

A hallmark of severe acute respiratory syndrome virus (SARS-CoV-2) replication is the discontinuous transcription of open reading frames (ORFs) encoding structural virus proteins. Real-time reverse transcription PCR (RT-qPCR) assays in previous publications used either single or multiplex assays for SARS-CoV-2 genomic RNA detection and a singleplex approach for subgenomic RNA detection. Although multiplex approaches often target multiple genomic RNA segments, an assay that concurrently detects genomic and subgenomic targets has been lacking. To bridge this gap, we developed two duplex one-step RT-qPCR assays that detect SARS-CoV-2 genomic ORF1a and either subgenomic spike or subgenomic ORF3a RNAs. All primers and probes for our assays were designed to bind to variants of SARS-CoV-2. In this study, our assays successfully detected SARS-CoV-2 Washington strain and delta variant isolates at various time points during the course of live virus infection in vitro. The ability to quantify subgenomic SARS-CoV-2 RNA is important, as it may indicate the presence of active replication, particularly in samples collected longitudinally. Furthermore, specific detection of genomic and subgenomic RNAs simultaneously in a single reaction increases assay efficiency, potentially leading to expedited lucidity about viral replication and pathogenesis of any variant of SARS-CoV-2.

Background: Ebola virus disease (EVD) survivors are at risk for uveitis during convalescence. Vision loss has been observed following uveitis due to cataracts. Since Ebola virus (EBOV) may persist in the ocular fluid of EVD survivors for an unknown duration, there are questions about the safety and feasibility of vision restorative cataract surgery in EVD survivors. Methods: We conducted a cross-sectional study of EVD survivors anticipating cataract surgery and patients with active uveitis to evaluate EBOV RNA persistence in ocular fluid, as well as vision outcomes post cataract surgery. Patients with aqueous humor that tested negative for EBOV RNA were eligible to proceed with manual small incision cataract surgery (MSICS). Findings: We screened 137 EVD survivors from June 2016 – August 2017 for enrolment. We enrolled 50 EVD survivors; 46 with visually significant cataract, 1 with a subluxated lens, 2 with active uveitis and 1 with a blind painful eye due to uveitis. The median age was 24.0 years (IQR 17–35) and 35 patients (70%) were female. The median logMAR visual acuity (VA) was 3.0 (Snellen VA Hand motions; Interquartile Range, IQR: 1.2-3.0, Snellen VA 20/320 – Hand motions). All patients tested negative for EBOV RNA by RT-PCR in aqueous humor/vitreous fluid and conjunctiva at a median of 19 months (IQR 18-20) from EVD diagnosis in Phase 1 of ocular fluid sampling and 34 months (IQR 32-36) from EVD diagnosis in Phase 2 of ocular fluid sampling. Thirty-four patients underwent MSICS, with a preoperative median VA improvement from hand motions to 20/30 at three-month postoperative follow-up (P

BACKGROUND:In the wake of the West African Ebola virus disease (EVD) outbreak of 2014-2016, thousands of EVD survivors began to manifest a constellation of systemic and ophthalmic sequelae. Besides systemic arthralgias, myalgias, and abdominal pain, patients were developing uveitis, a spectrum of inflammatory eye disease leading to eye pain, redness, and vision loss. To investigate this emerging eye disease, resources and equipment were needed to promptly evaluate this sight-threatening condition, particularly given our identification of Ebola virus in the ocular fluid of an EVD survivor during disease convalescence. METHODOLOGY/PRINCIPAL FINDINGS:A collaborative effort involving ophthalmologists, infectious disease specialists, eye care nurses, and physician leadership at Eternal Love Winning Africa (ELWA) Hospital in Liberia led to the development of a unique screening eye clinic for EVD survivors to screen, treat, and refer patients for more definitive care. Medications, resources, and equipment were procured from a variety of sources including discount websites, donations, purchasing with humanitarian discounts, and limited retail to develop a screening eye clinic and rapidly perform detailed ophthalmologic exams. Findings were documented in 96 EVD survivors to inform public health officials and eye care providers of the emerging disease process. Personal protective equipment was tailored to the environment and implications of EBOV persistence within intraocular fluid. CONCLUSIONS/SIGNIFICANCE:A screening eye clinic was feasible and effective for the rapid screening, care, and referral of EVD survivors with uveitis and retinal disease. Patients were screened promptly for an initial assessment of the disease process, which has informed other efforts within West Africa related to immediate patient care needs and our collective understanding of EVD sequelae. Further attention is needed to understand the pathogensis and treatment of ophthalmic sequelae given recent EVD outbreaks in West Africa and ongoing outbreak within Democratic Republic of Congo.

AimChristchurch, New Zealand, experienced two major earthquakes on 4th September 2010 and 22nd February 2011. Previous studies have demonstrated that earthquakes are associated with sudden cardiac deaths. Whilst myocardial ischemia would contribute to this, ventricular arrhythmia triggered by stress has also been suggested. We aim to study the impact of the two earthquakes on ventricular arrhythmia events.MethodsWe conducted a retrospective review of all patients resident in the earthquake zone with implantable defibrillators. Ventricular arrhythmia requiring therapy and non-sustained events were recorded from the period of 30 days before thru 30 days after the two earthquakes. Weekly event rates were calculated and compared using log rank analysis. Results are expressed as mean (range), significance was determined at the ResultsFor the 211 patients who were exposed to the 2010 earthquake, there was no difference in the proportion of patients free of therapy, either Shock or ATP (0.943 before and 0.933 after the earthquake, p = 0.85, ns). Similarly, there was no significant increase in events requiring therapy in the 236 patients exposed to the 2011 earthquake (0.957 before and 0.961 after the earthquake, p = 0.80, ns). We identified one patient who required multiple therapy for ventricular tachycardia immediately following both earthquakes.ConclusionThe two Christchurch earthquakes were not associated with an increase in the event rate of either sustained or non-sustained ventricular arrhythmias in our patients. We identified only a single patient who had arrhythmic storms immediately following the earthquakes.

Ongoing Ebola virus disease outbreaks in the Democratic Republic of the Congo follow the largest recorded outbreak in Western Africa (2013–2016). To combat outbreaks, testing of medical countermeasures (therapeutics or vaccines) requires a well-defined, reproducible, animal model. Here we present Ebola virus disease kinetics in 24 Chinese-origin rhesus monkeys exposed intramuscularly to a highly characterized, commercially available Kikwit Ebola virus Filovirus Animal Non-Clinical Group (FANG) stock. Until reaching predetermined clinical disease endpoint criteria, six animals underwent anesthesia for repeated clinical sampling and were compared to six that did not. Groups of three animals were euthanized and necropsied on days 3, 4, 5, and 6 post-exposure, respectively. In addition, three uninfected animals served as controls. Here, we present detailed characterization of clinical and laboratory disease kinetics and complete blood counts, serum chemistries, Ebola virus titers, and disease kinetics for future medical countermeasure (MCM) study design and control data. We measured no statistical difference in hematology, chemistry values, or time to clinical endpoint in animals that were anesthetized for clinical sampling during the acute disease compared to those that were not.

BACKGROUND: The Integrated Infectious Diseases Capacity Building Evaluation (IDCAP) designed two interventions: Integrated Management of Infectious Disease (IMID) training program and On-Site Support (OSS). We evaluated their effects on 23 facility performance indicators, including malaria case management. METHODOLOGY: IMID, a three-week training with two follow-up booster courses, was for two mid- level practitioners, primarily clinical officers and registered nurses, from 36 primary care facilities. OSS was two days of training and continuous quality improvement activities for nine months at 18 facilities, to which all health workers were invited to participate. Facilities were randomized as clusters 1∶1 to parallel OSS "arm A" or control "arm B". Outpatient data on four malaria case management indicators were collected for 14 months. Analysis compared changes before and during the interventions within arms (relative risk = RR). The effect of OSS was measured with the difference in changes across arms (ratio of RR = RRR). FINDINGS: The proportion of patients with suspected malaria for whom a diagnostic test result for malaria was recorded decreased in arm B (adjusted RR (aRR) = 0.97; 99%CI: 0.82,1.14) during IMID, but increased 25% in arm A (aRR = 1.25; 99%CI:0.94, 1.65) during IMID and OSS relative to baseline; (aRRR = 1.28; 99%CI:0.93, 1.78). The estimated proportion of patients that received an appropriate antimalarial among those prescribed any antimalarial increased in arm B (aRR = 1.09; 99%CI: 0.87, 1.36) and arm A (aRR = 1.50; 99%CI: 1.04, 2.17); (aRRR = 1.38; 99%CI: 0.89, 2.13). The proportion of patients with a negative diagnostic test result for malaria prescribed an antimalarial decreased in arm B (aRR = 0.96; 99%CI: 0.84, 1.10) and arm A (aRR = 0.67; 99%CI: 0.46, 0.97); (aRRR = 0.70; 99%CI: 0.48, 1.00). The proportion of patients with a positive diagnostic test result for malaria prescribed an antibiotic did not change significantly in either arm. INTERPRETATION: The combination of IMID and OSS was associated with statistically significant improvements in malaria case management.

The effects of two interventions, Integrated Management of Infectious Disease (IMID) training program and On-Site Support (OSS), were tested on 23 facility performance indicators for emergency triage assessment and treatment (ETAT), malaria, pneumonia, tuberculosis, and HIV.The trial was implemented in 36 primary care facilities in Uganda. From April 2010, two mid-level practitioners per facility participated in IMID training. Eighteen of 36 facilities were randomly assigned to Arm A, and received OSS in 2010 (nine monthly two-day sessions); 18 facilities assigned to Arm B did not receive OSS in 2010. Data were collected from Nov 2009 to Dec 2010 using a revised Ministry of Health outpatient medical form and nine registers. We analyzed the effect of IMID training alone by measuring changes before and during IMID training in Arm B, the combined effect of IMID training and OSS by measuring changes in Arm A, and the incremental effect of OSS by comparing changes across Arms A and B.IMID training was associated with statistically significant improvement in three indicators: outpatients triaged (adjusted relative risks (aRR) = 1.29, 99%CI = 1.01,1.64), emergency and priority patients admitted, detained, or referred (aRR = 1.59, 99%CI = 1.04,2.44), and pneumonia suspects assessed (aRR = 2.31, 99%CI = 1.50,3.55). IMID training and OSS combined was associated with improvements in six indicators: three ETAT indicators (outpatients triaged (aRR = 2.03, 99%CI = 1.13,3.64), emergency and priority patients admitted, detained or referred (aRR = 3.03, 99%CI = 1.40,6.56), and emergency patients receiving at least one appropriate treatment (aRR = 1.77, 99%CI = 1.10,2.84)); two malaria indicators (malaria cases receiving appropriate antimalarial (aRR = 1.50, 99%CI = 1.04,2.17), and patients with negative malaria test results prescribed antimalarial (aRR = 0.67, 99%CI = 0.46,0.97)); and enrollment in HIV care (aRR = 1.58, 99%CI = 1.32,1.89). OSS was associated with incremental improvement in emergency patients receiving at least one appropriate treatment (adjusted ratio of RR = 1.84,99%CI = 1.09,3.12).The trial showed that the OSS intervention significantly improved performance in one of 23 facility indicators.

BACKGROUND: Christchurch, New Zealand, was struck by 2 major earthquakes at 4:36 am on 4 September 2010, magnitude 7.1 and at 12:51 pm on 22 February 2011, magnitude 6.3. Both events caused widespread destruction. Christchurch Hospital was the region's only acute care hospital. It remained functional following both earthquakes. We were able to examine the effects of the 2 earthquakes on acute cardiac presentations. METHODS: Patients admitted under Cardiology in Christchurch Hospital 3 week prior to and 5 weeks following both earthquakes were analysed, with corresponding control periods in September 2009 and February 2010. Patients were categorised based on diagnosis: ST elevation myocardial infarction, Non ST elevation myocardial infarction, stress cardiomyopathy, unstable angina, stable angina, non cardiac chest pain, arrhythmia and others. RESULTS: There was a significant increase in overall admissions (p

Best practices for training mid-level practitioners (MLPs) to improve global health-services are not well-characterized. Two hypotheses were: 1) Integrated Management of Infectious Disease (IMID) training would improve clinical competence as tested with a single arm, pre-post design, and 2) on-site support (OSS) would yield additional improvements as tested with a cluster-randomized trial.Thirty-six Ugandan health facilities (randomized 1∶1 to parallel OSS and control arms) enrolled two MLPs each. All MLPs participated in IMID (3-week core course, two 1-week boost sessions, distance learning). After the 3-week course, OSS-arm trainees participated in monthly OSS. Twelve written case scenarios tested clinical competencies in HIV/AIDS, tuberculosis, malaria, and other infectious diseases. Each participant completed different randomly-assigned blocks of four scenarios before IMID (t0), after 3-week course (t1), and after second boost course (t2, 24 weeks after t1). Scoring guides were harmonized with IMID content and Ugandan national policy. Score analyses used a linear mixed-effects model. The primary outcome measure was longitudinal change in scenario scores.Scores were available for 856 scenarios. Mean correct scores at t0, t1, and t2 were 39.3%, 49.1%, and 49.6%, respectively. Mean score increases (95% CI, p-value) for t0-t1 (pre-post period) and t1-t2 (parallel-arm period) were 12.1 ((9.6, 14.6), p

BACKGROUND:In early clinical studies, the live tuberculosis vaccine Mycobacterium bovis BCG exhibited 80% protective efficacy against pulmonary tuberculosis (TB). Although BCG still exhibits reliable protection against TB meningitis and miliary TB in early childhood it has become less reliable in protecting against pulmonary TB. During decades of in vitro cultivation BCG not only lost some genes due to deletions of regions of the chromosome but also underwent gene duplication and other mutations resulting in increased antioxidant production. METHODOLOGY/PRINCIPAL FINDINGS:To determine whether microbial antioxidants influence vaccine immunogenicity, we eliminated duplicated alleles encoding the oxidative stress sigma factor SigH in BCG Tice and reduced the activity and secretion of iron co-factored superoxide dismutase. We then used assays of gene expression and flow cytometry with intracellular cytokine staining to compare BCG-specific immune responses in mice after vaccination with BCG Tice or the modified BCG vaccine. Compared to BCG, the modified vaccine induced greater IL-12p40, RANTES, and IL-21 mRNA in the spleens of mice at three days post-immunization, more cytokine-producing CD8+ lymphocytes at the peak of the primary immune response, and more IL-2-producing CD4+ lymphocytes during the memory phase. The modified vaccine also induced stronger secondary CD4+ lymphocyte responses and greater clearance of challenge bacilli. CONCLUSIONS/SIGNIFICANCE:We conclude that antioxidants produced by BCG suppress host immune responses. These findings challenge the hypothesis that the failure of extensively cultivated BCG vaccines to prevent pulmonary tuberculosis is due to over-attenuation and suggest instead a new model in which BCG evolved to produce more immunity-suppressing antioxidants. By targeting these antioxidants it may be possible to restore BCG's ability to protect against pulmonary TB.