An assessment of the impact of formal and informal messages about COVID-19 on the knowledge and practices for prevention and control among rural and urban communities in Ecuador

This study was conducted to evaluate the impact of formal and informal messages transmitted to urban and rural communities in Ecuador, on the knowledge of prevention and control of the SARS-CoV-2 pandemic. Six focus groups were carried out with six to eight people per group through Zoom platform, from August 2020 to April 2021;NVivo 12 software was used for the thematic analysis of the data. Thirtynine people, including male and female, participated in the study with mean age 39 years. Main outcomes included: use of alternative medicine for prevention and control of COVID-19;religious acceptance;impact of COVID-19 on mental health;lack of understanding and knowledge of the disease;and the mixed messages shared through official and unofficial channels about virus prevention and control. The study demonstrates the importance of using formal channels of communication to transmit accurate information, to reach people regardless of their geographical location. © 2023 Author(s).

Development of an amplicon-based sequencing approach in response to the global emergence of mpox.

The 2022 multicountry mpox outbreak concurrent with the ongoing Coronavirus Disease 2019 (COVID-19) pandemic further highlighted the need for genomic surveillance and rapid pathogen whole-genome sequencing. While metagenomic sequencing approaches have been used to sequence many of the early mpox infections, these methods are resource intensive and require samples with high viral DNA concentrations. Given the atypical clinical presentation of cases associated with the outbreak and uncertainty regarding viral load across both the course of infection and anatomical body sites, there was an urgent need for a more sensitive and broadly applicable sequencing approach. Highly multiplexed amplicon-based sequencing (PrimalSeq) was initially developed for sequencing of Zika virus, and later adapted as the main sequencing approach for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Here, we used PrimalScheme to develop a primer scheme for human monkeypox virus that can be used with many sequencing and bioinformatics pipelines implemented in public health laboratories during the COVID-19 pandemic. We sequenced clinical specimens that tested presumptively positive for human monkeypox virus with amplicon-based and metagenomic sequencing approaches. We found notably higher genome coverage across the virus genome, with minimal amplicon drop-outs, in using the amplicon-based sequencing approach, particularly in higher PCR cycle threshold (Ct) (lower DNA titer) samples. Further testing demonstrated that Ct value correlated with the number of sequencing reads and influenced the percent genome coverage. To maximize genome coverage when resources are limited, we recommend selecting samples with a PCR Ct below 31 Ct and generating 1 million sequencing reads per sample. To support national and international public health genomic surveillance efforts, we sent out primer pool aliquots to 10 laboratories across the United States, United Kingdom, Brazil, and Portugal. These public health laboratories successfully implemented the human monkeypox virus primer scheme in various amplicon sequencing workflows and with different sample types across a range of Ct values. Thus, we show that amplicon-based sequencing can provide a rapidly deployable, cost-effective, and flexible approach to pathogen whole-genome sequencing in response to newly emerging pathogens. Importantly, through the implementation of our primer scheme into existing SARS-CoV-2 workflows and across a range of sample types and sequencing platforms, we further demonstrate the potential of this approach for rapid outbreak response.

Factors affecting the implementation of employee whole health in the veterans health administration: a qualitative evaluation.

BACKGROUND: There is increasing recognition of the need to focus on the health and well-being of healthcare employees given high rates of burnout and turnover. Employee wellness programs are effective at addressing these issues; however, participation in these programs is often a challenge and requires large scale organizational transformation. The Veterans Health Administration (VA) has begun to roll out their own employee wellness program-Employee Whole Health (EWH)-focused on the holistic needs of all employees. This evaluation's goal was to use the Lean Enterprise Transformation (LET) model for organizational transformation to identify key factors-facilitators and barriers-affecting the implementation of VA EWH. METHODS: This cross-sectional qualitative evaluation based on the action research model reflects on the organizational implementation of EWH. Semi-structured 60-minute phone interviews were conducted in February-April 2021 with 27 key informants (e.g., EWH coordinator, wellness/occupational health staff) knowledgeable about EWH implementation across 10 VA medical centers. Operational partner provided a list of potential participants, eligible because of their involvement in EWH implementation at their site. The interview guide was informed by the LET model. Interviews were recorded and professionally transcribed. Constant comparative review with a combination of a priori coding based on the model and emergent thematic analysis was used to identify themes from transcripts. Matrix analysis and rapid turnaround qualitative methods were used to identify cross-site factors to EWH implementation. RESULTS: Eight common factors in the conceptual model were found to facilitate and/or hinder EWH implementation efforts: [1] EWH initiatives, [2] multilevel leadership support, [3] alignment, [4] integration, [5] employee engagement, [6] communication, [7] staffing, and [8] culture. An emergent factor was [9] the impact of the COVID-19 pandemic on EWH implementation. CONCLUSIONS: As VA expands its EWH cultural transformation nationwide, evaluation findings can (a) enable existing programs to address known implementation barriers, and (b) inform new sites to capitalize on known facilitators, anticipate and address barriers, and leverage evaluation recommendations through concerted implementation at the organization, process, and employee levels to jump-start their EWH program implementation.

COVID-19 impact on EuroTravNet infectious diseases sentinel surveillance in Europe.

BACKGROUND: The COVID-19 pandemic resulted in a sharp decline of post-travel patient encounters at the European sentinel surveillance network (EuroTravNet) of travellers' health. We report on the impact of COVID-19 on travel-related infectious diseases as recorded by EuroTravNet clinics. METHODS: Travelers who presented between January 1, 2019 and September 30, 2021 were included. Comparisons were made between the pre-pandemic period (14 months from January 1, 2019 to February 29, 2020); and the pandemic period (19 months from March 1, 2020 to September 30, 2021). RESULTS: Of the 15,124 visits to the network during the 33-month observation period, 10,941 (72%) were during the pre-pandemic period, and 4183 (28%) during the pandemic period. Average monthly visits declined from 782/month (pre-COVID-19 era) to 220/month (COVID-19 pandemic era). Among non-migrants, the top-10 countries of exposure changed after onset of the COVID-19 pandemic; destinations such as Italy and Austria, where COVID-19 exposure peaked in the first months, replaced typical travel destinations in Asia (Thailand, Indonesia, India). There was a small decline in migrant patients reported, with little change in the top countries of exposure (Bolivia, Mali). The three top diagnoses with the largest overall decreases in relative frequency were acute gastroenteritis (-5.3%), rabies post-exposure prophylaxis (-2.8%), and dengue (-2.6%). Apart from COVID-19 (which rose from 0.1% to 12.7%), the three top diagnoses with the largest overall relative frequency increase were schistosomiasis (+4.9%), strongyloidiasis (+2.7%), and latent tuberculosis (+2.4%). CONCLUSIONS: A marked COVID-19 pandemic-induced decline in global travel activities is reflected in reduced travel-related infectious diseases sentinel surveillance reporting.

Analisis Del Impacto Del Covid-19 En Pacientes Con Enfermedad Inflamatoria Intestinal Empleando Inteligencia Artificial (Savana Manager)

Introduccion: Estudiamos el impacto del COVID-19 en pacientes con Enfermedad Inflamatoria Intestinal (EII) en Castilla-La Mancha. Metodos: Estudio observacional retrospectivo utilizando inteligencia artificial con capacidad de procesamiento de lenguaje natural, SAVANA manager. Esta herramienta, a pesar de sus sesgos (ej: duplicacion de casos), permite analizar grandes poblaciones. Analizamos datos de 1.808.010 pacientes durante 2020. Resultados: Se identificaron 2.243 pacientes con EII y COVID-19, que en comparacion con los casos de COVID-19 sin EII hubo mas hipertension arterial, diabetes mellitus, dislipemia, obesidad o tabaquismo. A pesar de ello, no se apreciaron diferencias en hospitalizacion (0,8607, 0,7320-1,0121, p = 0,0696), ingreso en UCI (0,4113, 0,1025-1,6508, p = 0,2102) o mortalidad (0,9099, 0,6123-1,3521, p = 0,6402). COVID-19 fue mas frecuente en pacientes con EII (3,6413, 3,4616-3,8303, p < 0,0001). Comparando pacientes con EII y COVID-19 segun sus tratamientos, vedolizumab es el unico con mayor riesgo de COVID-19 (0,3091, 0,0967-0,9886, p = 0,0478), sin embargo, el riesgo de hospitalizacion para vedolizumab es menor (0,3091, 0,0967-0,9886, p = 0,0478). Los inmunomoduladores tambien tienen un menor riesgo de hospitalizacion tanto solos (0,6677, 0,4650-0,9588, p = 0,0287) como combinados con anti-TNF (0,5109, 0,2836-0,9205, p = 0,0254). No se encontraron diferencias para monoterapia anti-TNF, ustekinumab o tofacitinib. La tasa de UCI y la mortalidad no son diferentes entre los tratamientos, salvo para tofacitinib (tasa de UCI 0,00%, mortalidad 10,00%), sin embargo, el pequeno numero de pacientes podrian sesgar este resultado. [Table presented] Conclusiones: COVID-19 en pacientes con EII no es diferente en hospitalizacion, ingreso en UCI o mortalidad en comparacion con la poblacion sin Ell. Los pacientes con Ell expuestos a inmunomoduladores y vedolizumab tienen menor riesgo de hospitalizacion que los no expuestos, no se encontraron diferencias para anti-TNF monoterapia o ustekinumab.Copyright © 2023 Elsevier Espana, S.L.U. Todos los derechos reservados.

COVID-19 in cancer patients: update from the joint analysis of the ESMO-CoCARE, BSMO, and PSMO international databases.

BACKGROUND: COVID-19 has significantly affected patients with cancer and revealed unanticipated challenges in securing optimal cancer care across different disciplines. The European Society for Medical Oncology COVID-19 and CAncer REgistry (ESMO-CoCARE) is an international, real-world database, collecting data on the natural history, management, and outcomes of patients with cancer and SARS-CoV-2 infection. METHODS: This is the 2nd CoCARE analysis, jointly with Belgian (Belgian Society of Medical Oncology, BSMO) and Portuguese (Portuguese Society of Medical Oncology, PSMO) registries, with data from January 2020 to December 2021. The aim is to identify significant prognostic factors for COVID-19 hospitalization and mortality (primary outcomes), as well as intensive care unit admission and overall survival (OS) (secondary outcomes). Subgroup analyses by pandemic phase and vaccination status were carried out. RESULTS: The cohort includes 3294 patients (CoCARE: 2049; BSMO: 928, all hospitalized by eligibility criteria; PSMO: 317), diagnosed in four distinct pandemic phases (January to May 2020: 36%; June to September 2020: 9%; October 2020 to February 2021: 41%; March to December 2021: 12%). COVID-19 hospitalization rate was 54% (CoCARE/PSMO), ICU admission 14%, and COVID-19 mortality 22% (all data). At a 6-month median follow-up, 1013 deaths were recorded with 73% 3-month OS rate. No significant change was observed in COVID-19 mortality among hospitalized patients across the four pandemic phases (30%-33%). Hospitalizations and ICU admission decreased significantly (from 78% to 34% and 16% to 10%, respectively). Among 1522 patients with known vaccination status at COVID-19 diagnosis, 70% were non-vaccinated, 24% had incomplete vaccination, and 7% complete vaccination. Complete vaccination had a protective effect on hospitalization (odds ratio = 0.24; 95% confidence interval [0.14-0.38]), ICU admission (odds ratio = 0.29 [0.09-0.94]), and OS (hazard ratio = 0.39 [0.20-0.76]). In multivariable analyses, COVID-19 hospitalization was associated with patient/cancer characteristics, the first pandemic phase, the presence of COVID-19-related symptoms or inflammatory biomarkers, whereas COVID-19 mortality was significantly higher in symptomatic patients, males, older age, ethnicity other than Asian/Caucasian, Eastern Cooperative Oncology Group performance status ≥2, body mass index <25, hematological malignancy, progressive disease versus no evident disease, and advanced cancer stage. CONCLUSIONS: The updated CoCARE analysis, jointly with BSMO and PSMO, highlights factors that significantly affect COVID-19 outcomes, providing actionable clues for further reducing mortality.

Age-related changes in plasma biomarkers and their association with mortality in COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19)-induced mortality occurs predominantly in older patients. Several immunomodulating therapies seem less beneficial in these patients. The biological substrate behind these observations is unknown. The aim of this study was to obtain insight into the association between ageing, the host response and mortality in patients with COVID-19. METHODS: We determined 43 biomarkers reflective of alterations in four pathophysiological domains: endothelial cell and coagulation activation, inflammation and organ damage, and cytokine and chemokine release. We used mediation analysis to associate ageing-driven alterations in the host response with 30-day mortality. Biomarkers associated with both ageing and mortality were validated in an intensive care unit and external cohort. RESULTS: 464 general ward patients with COVID-19 were stratified according to age decades. Increasing age was an independent risk factor for 30-day mortality. Ageing was associated with alterations in each of the host response domains, characterised by greater activation of the endothelium and coagulation system and stronger elevation of inflammation and organ damage markers, which was independent of an increase in age-related comorbidities. Soluble tumour necrosis factor receptor 1, soluble triggering receptor expressed on myeloid cells 1 and soluble thrombomodulin showed the strongest correlation with ageing and explained part of the ageing-driven increase in 30-day mortality (proportion mediated: 13.0%, 12.9% and 12.6%, respectively). CONCLUSIONS: Ageing is associated with a strong and broad modification of the host response to COVID-19, and specific immune changes likely contribute to increased mortality in older patients. These results may provide insight into potential age-specific immunomodulatory targets in COVID-19.

Analysis of the ARTIC V4 and V4.1 SARS-CoV-2 primers and their impact on the detection of Omicron BA.1 and BA.2 lineage-defining mutations.

The ARTIC protocol uses a multiplexed PCR approach with two primer pools tiling the entire SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) genome. Primer pool updates are necessary for accurate amplicon sequencing of evolving SARS-CoV-2 variants with novel mutations. The suitability of the ARTIC V4 and updated V4.1 primer scheme was assessed using whole genome sequencing of Omicron from clinical samples using Oxford Nanopore Technology. Analysis of Omicron BA.1 genomes revealed that 93.22 % of clinical samples generated improved genome coverage at 50× read depth with V4.1 primers when compared to V4 primers. Additionally, the V4.1 primers improved coverage of BA.1 across amplicons 76 and 88, which resulted in the detection of the variant-defining mutations G22898A, A26530G and C26577G. The Omicron BA.2 sub-variant (VUI-22JAN-01) replaced BA.1 as the dominant variant by March 2022, and analysis of 168 clinical samples showed reduced coverage across amplicons 15 and 75. Upon further interrogation of primer binding sites, a mutation at C4321T [present in 163/168 (97 %) of samples] was identified as a possible cause of complete dropout of amplicon 15. Furthermore, two mutations were identified within the primer binding regions for amplicon 75: A22786C (present in 90 % of samples) and C22792T (present in 12.5 % of samples). Together, these mutations may result in reduced coverage of amplicon 75, and further primer updates would allow the identification of the two BA.2-defining mutations present in amplicon 75: A22688G and T22679C. This work highlights the need for ongoing surveillance of primer matches as circulating variants evolve and change.

Genomics-informed outbreak investigations of SARS-CoV-2 using civet

The scale of data produced during the SARS-CoV-2 pandemic has been unprecedented, with more than 13 million sequences shared publicly at the time of writing. This wealth of sequence data provides important context for interpreting local outbreaks. However, placing sequences of interest into national and international context is difficult given the size of the global dataset. Often outbreak investigations and genomic surveillance efforts require running similar analyses again and again on the latest dataset and producing reports. We developed civet (cluster investigation and virus epidemiology tool) to aid these routine analyses and facilitate virus outbreak investigation and surveillance. Civet can place sequences of interest in the local context of background diversity, resolving the query into different 'catchments' and presenting the phylogenetic results alongside metadata in an interactive, distributable report. Civet can be used on a fine scale for clinical outbreak investigation, for local surveillance and cluster discovery, and to routinely summarise the virus diversity circulating on a national level. Civet reports have helped researchers and public health bodies feedback genomic information in the appropriate context within a timeframe that is useful for public health.

The impact of COVID-19 on patients with Inflammatory Bowel Disease: A population-based study using artificial intelligence

Background: Coronavirus disease 2019 (COVID-19) has been a pandemic that is still very prevalent. Patients with Inflammatory Bowel Disease (IBD) represent a special population considering their already altered immune system and their exposure to several immunosuppressive therapies. We pretend to study the impact of COVID-19 on IBD patients in our community, Castilla-La Mancha (a region in central Spain). Method(s): Retrospective observational study using an artificial intelligence with natural language processing capability, the SAVANA manager, we analyzed data from 1 808 010 patients with Electronic Medical Records (EMR) within the public health system of Castilla-La Mancha from March 1st 2020 to January 1st 2021. Data on demographic characteristics, hospitalization, ICU admission and mortality were collected. We compared COVID outcomes between IBD and non-IBD patients. We compared COVID outcomes in IBD patients according to their treatment (comparing each treatment group to those IBD patients with no treatment);we considered: Immunomodulators (azathioprine, mercaptopurine, methotrexate), antiTNF alone or combined with immunomodulator, vedolizumab, ustekinumab and tofacitinib;mesalazine and corticosteroids were not analyzed. Result(s): 2 243 patients with IBD suffered COVID-19, compared to COVID-19 cases without IBD there were less females, they suffered more arterial hypertension, diabetes mellitus, dyslipidemia, obesity, or tabacco use (TABLE 1). And yet, despite these being proven risk factors for worse outcomes for COVID-19, no differences were appreciated in hospitalization rate, ICU admission, or mortality between those with or without IBD (TABLE 2). COVID-19 was more frequent in IBD patients (32.59 vs 13.28%). Comparing IBD patients with COVID-19 according to their treatments (TABLE 3), vedolizumab is the only treatment with a higher risk for COVID-19 infection, however the hospitalization risk for vedolizumab is lower than for those without it. Immunomodulators do also have a lower hospitalization risk both alone or in combination with antiTNF, no differences were found for antiTNF monotherapy, ustekinumab or tofacitinib. ICU rate and mortality are no different between treatments, except for tofacitinib (0.00% ICU rate, 10.00% mortality), however the small number of patients using this treatment may bias this result. Conclusion(s): COVID-19 in IBD patients is no different in hospitalization, ICU admission or mortality compared to non-IBD population. IBD patients exposed to immunomodulators and vedolizumab have less hospitalization risk than those not exposed, no differences were found for antiTNF alone or ustekinumab. The impact of tofacitinib in COVID outcomes requires further investigation.

COVID and US farm labor. (Special Issue: The global race for migrant labour: pandemic contradictions.)

Many governments closed their borders in spring 2020 to prevent the spread of Covid, but they also made exceptions to allow farm employers to recruit temporary foreign workers to fill seasonal farm jobs. The pandemic changed many parameters of food systems. Closed restaurants led to widespread layoffs in leisure and hospitality, rates of Covid were high among nonfarm food processing and meatpacking workers, and there was less Covid than expected among the foreign workers who increased their share of employment in production agriculture. The pandemic accelerated three major changes that were already underway, viz., more labor-saving mechanization, more foreign workers, and increased imports of labor-intensive commodities. Mechanization increases the resilience of production agriculture to labor supply shocks.

Sustained increase in depression and anxiety among psychiatrically healthy adolescents during late stage COVID-19 pandemic.

Background: Adolescents have experienced increases in anxiety, depression, and stress during the COVID-19 pandemic and may be at particular risk for suffering from long-term mental health consequences because of their unique developmental stage. This study aimed to determine if initial increases in depression and anxiety in a small sample of healthy adolescents after the onset of the COVID-19 pandemic were sustained at follow-up during a later stage of the pandemic. Methods: Fifteen healthy adolescents completed self-report measures at three timepoints (pre-pandemic [T1], early pandemic [T2], and later pandemic [T3]). The sustained effect of COVID-19 on depression and anxiety was examined using linear mixed-effect analyses. An exploratory analysis was conducted to investigate the relationship between difficulties in emotion regulation during COVID-19 at T2 and increases in depression and anxiety at T3. Results: The severity of depression and anxiety was significantly increased at T2 and sustained at T3 (depression: Hedges' g [T1 to T2] = 1.04, g [T1 to T3] = 0.95; anxiety: g [T1 to T2] = 0.79, g [T1 to T3] = 0.80). This was accompanied by sustained reductions in positive affect, peer trust, and peer communication. Greater levels of difficulties in emotion regulation at T2 were related to greater symptoms of depression and anxiety at T3 (rho = 0.71 to 0.80). Conclusion: Increased symptoms of depression and anxiety were sustained at the later stage of the pandemic in healthy adolescents. Replication of these findings with a larger sample size would be required to draw firm conclusions.

Genomics-informed outbreak investigations of SARS-CoV-2 using civet.

The scale of data produced during the SARS-CoV-2 pandemic has been unprecedented, with more than 13 million sequences shared publicly at the time of writing. This wealth of sequence data provides important context for interpreting local outbreaks. However, placing sequences of interest into national and international context is difficult given the size of the global dataset. Often outbreak investigations and genomic surveillance efforts require running similar analyses again and again on the latest dataset and producing reports. We developed civet (cluster investigation and virus epidemiology tool) to aid these routine analyses and facilitate virus outbreak investigation and surveillance. Civet can place sequences of interest in the local context of background diversity, resolving the query into different 'catchments' and presenting the phylogenetic results alongside metadata in an interactive, distributable report. Civet can be used on a fine scale for clinical outbreak investigation, for local surveillance and cluster discovery, and to routinely summarise the virus diversity circulating on a national level. Civet reports have helped researchers and public health bodies feedback genomic information in the appropriate context within a timeframe that is useful for public health.

Covid and US Farm Labor

Many governments closed their borders in spring 2020 to prevent the spread of Covid, but they also made exceptions to allow farm employers to recruit temporary foreign workers to fill seasonal farm jobs. The pandemic changed many parameters of food systems. Closed restaurants led to widespread layoffs in leisure and hospitality, rates of Covid were high among nonfarm food processing and meatpacking workers, and there was less Covid than expected among the foreign workers who increased their share of employment in production agriculture. The pandemic accelerated three major changes that were already underway, viz., more labor-saving mechanization, more foreign workers, and increased imports of labor-intensive commodities. Mechanization increases the resilience of production agriculture to labor supply shocks. © 2023 Taylor & Francis Group, LLC.

Bacillus Calmette-Guérin vaccine for prevention of COVID-19 and other respiratory tract infections in older adults with comorbidities: a randomized controlled trial

Objectives To test whether BCG vaccination would reduce the incidence of COVID-19 and other respiratory tract infections in older adults with one or more comorbidities. Methods Community-dwelling adults over 60 years old with one or more underlying comorbidities and no contra-indications for BCG vaccination were randomized 1:1 to BCG or placebo vaccination and followed for six months. The primary endpoint was self-reported test-confirmed COVID-19 incidence. Secondary endpoints included COVID-19 hospital admissions and clinically relevant RTI (i.e. RTI including but not limited to COVID-19 requiring medical intervention). COVID-19 and clinically relevant RTI episodes were adjudicated. Incidences were compared using Fine and Gray regression, accounting for competing events. Results A total of 6,112 participants with a median age of 69 years (inter-quartile range 65-74) and median of 2 (inter-quartile range 1-3) comorbidities were randomized to BCG (n=3,058) or placebo (n=3,054) vaccination. COVID-19 infections were reported by 129 BCG recipients compared to 115 placebo recipients (hazard ratio (HR) 1.12;95% confidence interval (CI) 0.87-1.44). COVID-19-related hospitalization occurred in 18 BCG and 21 placebo recipients (HR 0.86;95% CI 0.46-1.61). During the study period 13 BCG recipients compared to 18 placebo recipients died (HR 0.71;95% CI 0.35 - 1.43) of which 11 deaths (35%) were COVID-19 related six in the placebo group and five in the BCG group. Clinically relevant RTI was reported by 66 BCG and 72 placebo recipients (HR 0.92;95% CI 0.66-1.28). Conclusion BCG vaccination does not protect older adults with comorbidities against COVID-19, COVID-19 hospitalization or clinically relevant RTI.

Biochemical analysis of SARS-CoV-2 Nsp13 helicase implicated in COVID-19 and factors that regulate its catalytic functions.

Replication of the 30-kilobase genome of SARS-CoV-2, responsible for COVID-19, is a key step in the coronavirus life cycle that requires a set of virally encoded nonstructural proteins such as the highly conserved Nsp13 helicase. However, the features that contribute to catalytic properties of Nsp13 are not well established. Here, we biochemically characterized the purified recombinant SARS-CoV-2 Nsp13 helicase protein, focusing on its catalytic functions, nucleic acid substrate specificity, nucleotide/metal cofactor requirements, and displacement of proteins from RNA molecules proposed to be important for its proofreading role during coronavirus replication. We determined that Nsp13 preferentially interacts with single-stranded DNA compared with single-stranded RNA to unwind a partial duplex helicase substrate. We present evidence for functional cooperativity as a function of Nsp13 concentration, which suggests that oligomerization is important for optimal activity. In addition, under single-turnover conditions, Nsp13 unwound partial duplex RNA substrates of increasing double-stranded regions (16-30 base pairs) with similar efficiency, suggesting the enzyme unwinds processively in this range. We also show Nsp13-catalyzed RNA unwinding is abolished by a site-specific neutralizing linkage in the sugar-phosphate backbone, demonstrating continuity in the helicase-translocating strand is essential for unwinding the partial duplex substrate. Taken together, we demonstrate for the first time that coronavirus helicase Nsp13 disrupts a high-affinity RNA-protein interaction in a unidirectional and ATP-dependent manner. Furthermore, sensitivity of Nsp13 catalytic functions to Mg2+ concentration suggests a regulatory mechanism for ATP hydrolysis, duplex unwinding, and RNA protein remodeling, processes implicated in SARS-CoV-2 replication and proofreading.

Bacillus Calmette-Guérin vaccine for prevention of COVID-19 and other respiratory tract infections in older adults with comorbidities: a randomized controlled trial.

OBJECTIVES: To test whether Bacillus Calmette-Guérin (BCG) vaccination would reduce the incidence of COVID-19 and other respiratory tract infections (RTIs) in older adults with one or more comorbidities. METHODS: Community-dwelling adults aged 60 years or older with one or more underlying comorbidities and no contraindications to BCG vaccination were randomized 1:1 to BCG or placebo vaccination and followed for 6 months. The primary endpoint was a self-reported, test-confirmed COVID-19 incidence. Secondary endpoints included COVID-19 hospital admissions and clinically relevant RTIs (i.e. RTIs including but not limited to COVID-19 requiring medical intervention). COVID-19 and clinically relevant RTI episodes were adjudicated. Incidences were compared using Fine-Gray regression, accounting for competing events. RESULTS: A total of 6112 participants with a median age of 69 years (interquartile range, 65-74) and median of 2 (interquartile range, 1-3) comorbidities were randomized to BCG (n = 3058) or placebo (n = 3054) vaccination. COVID-19 infections were reported by 129 BCG recipients compared to 115 placebo recipients [hazard ratio (HR), 1.12; 95% CI, 0.87-1.44]. COVID-19-related hospitalization occurred in 18 BCG and 21 placebo recipients (HR, 0.86; 95% CI, 0.46-1.61). During the study period, 13 BCG recipients died compared with 18 placebo recipients (HR, 0.71; 95% CI, 0.35-1.43), of which 11 deaths (35%) were COVID-19-related: six in the placebo group and five in the BCG group. Clinically relevant RTI was reported by 66 BCG and 72 placebo recipients (HR, 0.92; 95% CI, 0.66-1.28). DISCUSSION: BCG vaccination does not protect older adults with comorbidities against COVID-19, COVID-19 hospitalization, or clinically relevant RTIs.