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19 pages, 508 KiB  
Article
Improved Survival in Malnourished COVID-19 Inpatients with Oral Nutrition Supplementation
by Tyrus Vong, Lisa R. Yanek, Laura E. Matarese, Berkeley N. Limketkai and Gerard E. Mullin
Nutrients 2025, 17(15), 2401; https://doi.org/10.3390/nu17152401 - 23 Jul 2025
Viewed by 282
Abstract
Background: Malnutrition is associated with adverse clinical and economic outcomes. We recently reported that the hospital mortality rate in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected inpatients was higher in malnourished patients than in those without malnutrition. The present study aimed to determine [...] Read more.
Background: Malnutrition is associated with adverse clinical and economic outcomes. We recently reported that the hospital mortality rate in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected inpatients was higher in malnourished patients than in those without malnutrition. The present study aimed to determine if SARS-CoV-2-infected inpatients who received oral nutrition supplementation (ONS) had improved survival. We performed a retrospective cohort study including 37,215 adults (aged 18 and older) admitted with COVID-19 to five Johns Hopkins–affiliated hospitals between 1 March 2020, and 31 March 2023. Malnutrition risk was initially screened using the Malnutrition Universal Screening Tool (MUST), with cases subsequently confirmed by registered dietitians via a standardized, validated assessment protocol. Logistic regression analysis predicting hospital mortality examined the association of ONS with hospital survival in SARS-CoV-2-infected inpatients, incorporating covariates and weights for ONS receipt. Results: Malnutrition was an independent predictor of higher hospital mortality from COVID-19 illness. The prevalence of malnutrition among adult inpatients with SARS-CoV-2 infection in our cohort was 15.22%. Inpatient adults with moderate or severe malnutrition in the context of acute illness or injury who were given ONS had lower odds of inpatient mortality (moderate OR = 0.72, 95% CI 0.62–0.85; severe OR = 0.76, 95% CI 0.67–0.87; both p < 0.001). Overweight and obese patients who received ONS had higher odds of inpatient mortality (overweight OR = 1.15, 95% CI 1.08–1.22, p < 0.0001; obese OR = 1.08, 95% CI 1.01–1.14, p = 0.02, respectively). For inpatients who were underweight, receiving ONS was protective against inpatient mortality (OR = 0.78, 95% CI 0.68–0.88, p = 0.0001). Thus, among adult inpatients with SARS-CoV-2 infection, malnourished and underweight individuals appeared to experience improved survival when provided with oral nutritional supplements (ONS), whereas overweight or obese patients remain at an elevated risk of mortality. The timing of ONS receipt in hospitalized patients with SARS-CoV-2 influenced mortality. Patients who had earlier time to ONS had 13% lower odds of inpatient mortality (OR = 0.87, 95% CI 0.79–0.97, p = 0.0105). Conclusions: In a cohort of SARS-CoV-2 adult inpatients, those with confirmed malnutrition receiving oral nutrition supplements had a higher likelihood of hospital survival. This is the first study demonstrating an association of oral nutrition intervention with reduced hospital mortality in malnourished SARS-CoV-2-infected adults. Full article
(This article belongs to the Section Clinical Nutrition)
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22 pages, 680 KiB  
Review
Adaptation of the Vaccine Prophylaxis Strategy to Variants of the SARS-CoV-2 Virus
by Sofia M. Gulova, Uliana S. Veselkina and Irina V. Astrakhantseva
Vaccines 2025, 13(7), 761; https://doi.org/10.3390/vaccines13070761 - 17 Jul 2025
Viewed by 622
Abstract
The emergence of a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus closely related to SARS-CoV and officially known as Betacoronavirus pandemicum precipitated a substantial surge in vaccine development that culminated during the global COVID-19 pandemic. At present, there are dozens of [...] Read more.
The emergence of a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus closely related to SARS-CoV and officially known as Betacoronavirus pandemicum precipitated a substantial surge in vaccine development that culminated during the global COVID-19 pandemic. At present, there are dozens of vaccines for the prevention of SARS-CoV-2 being utilized across the globe. However, only 10 of these vaccines have been authorized by the World Health Organization (WHO). These include mRNA-based, viral vector, subunit and whole-virion inactivated vaccines. At the current end of the pandemic, there has been a decline in the global vaccination rate, both for the general population and for those most at risk of severe illness from the virus. This suggests that the effectiveness of the vaccines may be waning. The decline occurs alongside a decrease in testing and sequencing for SARS-CoV-2. Furthermore, the process of tracking viruses becomes increasingly complex, thereby providing a selective advantage for SARS-CoV-2 and allowing it to evolve stealthily. In this review, we provide a comprehensive overview of viral evolution and vaccine development. We also discuss ways to overcome viral variability and test universal vaccines for all SARS-CoV-2 variants. Full article
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25 pages, 1428 KiB  
Article
Incidence and Risk Factors of Secondary Infections in Critically Ill SARS-CoV-2 Patients: A Retrospective Study in an Intensive Care Unit
by Mircea Stoian, Leonard Azamfirei, Adina Andone, Anca-Meda Văsieșiu, Andrei Stîngaciu, Adina Huțanu, Sergio Rareș Bândilă, Daniela Dobru, Andrei Manea and Adina Stoian
Biomedicines 2025, 13(6), 1333; https://doi.org/10.3390/biomedicines13061333 - 29 May 2025
Viewed by 659
Abstract
Background/Objectives: The clinical forms of coronavirus disease 2019 (COVID-19) vary widely in severity, ranging from asymptomatic or moderate cases to severe pneumonia that can lead to acute respiratory failure, acute respiratory distress syndrome, multiple organ dysfunction syndrome, and death. Our main objective [...] Read more.
Background/Objectives: The clinical forms of coronavirus disease 2019 (COVID-19) vary widely in severity, ranging from asymptomatic or moderate cases to severe pneumonia that can lead to acute respiratory failure, acute respiratory distress syndrome, multiple organ dysfunction syndrome, and death. Our main objective was to determine the prevalence of bacterial and fungal secondary infections in an intensive care unit (ICU). Secondary objectives included analyzing the impact of these infections on mortality and medical resource utilization, as well as assessing antimicrobial resistance in this context. Methods: We conducted a retrospective cohort study that included critically ill severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients treated in an ICU and analyzed the prevalence of co-infections and superinfections. Results: A multivariate analysis of mortality found that the presence of superinfections increased the odds of death by more than 15-fold, while the Sequential Organ Failure Assessment (SOFA) score and C-reactive protein (adjusted for confounders) increased the odds of mortality by 51% and 13%, respectively. The antibiotic resistance profile of microorganisms indicated a high prevalence of resistant strains. Carbapenems, glycopeptides, and oxazolidinones were the most frequently used classes of antibiotics. Among patients, 27.9% received a single antibiotic, 47.5% received two from different classes, and 24.4% were treated with three or more. Conclusions: The incidence and spectrum of bacterial and fungal superinfections are higher in critically ill ICU patients, leading to worse outcomes in COVID-19 cases. Multidrug-resistant pathogens present significant challenges for ICU and public health settings. Early screening, accurate diagnosis, and minimal use of invasive devices are essential to reduce risks and improve patient outcomes. Full article
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24 pages, 392 KiB  
Systematic Review
Long COVID: A Systematic Review of Preventive Strategies
by Sun O. Park and Neha Nanda
Infect. Dis. Rep. 2025, 17(3), 56; https://doi.org/10.3390/idr17030056 - 21 May 2025
Viewed by 2505
Abstract
Background: Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019, long COVID (LC) has become a significant global health burden. While knowledge about LC is accumulating, studies on its prevention are still lacking. Methods: We conducted a systematic [...] Read more.
Background: Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019, long COVID (LC) has become a significant global health burden. While knowledge about LC is accumulating, studies on its prevention are still lacking. Methods: We conducted a systematic review following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to investigate prevention options for LC. We identified fifteen articles on vaccines, seven on antivirals, and six on other interventions after searching for articles in the PubMed/MEDLINE database using the MeSH terms. Results: Most vaccine-related studies demonstrated a protective effect of COVID-19 vaccines against developing LC. Our review found an equivocal effect of antivirals, while metformin had a protective effect in outpatients and corticosteroids were protective in hospitalized patients against LC. Conversely, COVID-19 convalescent plasma and multiple micronutrient supplement did not confer any protection against LC. Conclusions: COVID-19 vaccination is vital as it not only prevents COVID-19 but also reduces the severity of illness and may help prevent LC. Further studies are warranted to shed light on preventive strategies for long COVID. Full article
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13 pages, 1256 KiB  
Article
Serial Changes in Vitamin D Status in Patients During Severe Acute Respiratory Distress Syndrome and Extracorporeal Membrane Oxygenation
by Martina Hermann, Jelena Poslussny, Gernot Gerger, Helmuth Haslacher, Georg Mayrhofer, Verena Eva Tretter, Mathias Maleczek and Cem Ekmekcioglu
Medicina 2025, 61(5), 901; https://doi.org/10.3390/medicina61050901 - 16 May 2025
Viewed by 510
Abstract
Background and Objectives: Therapeutic interventions, such as extracorporeal membrane oxygenation (ECMO) therapy, in patients suffering from severe acute respiratory distress syndrome (ARDS) may reduce their vitamin D levels. Many observational studies have shown associations between poor outcomes and low vitamin D levels [...] Read more.
Background and Objectives: Therapeutic interventions, such as extracorporeal membrane oxygenation (ECMO) therapy, in patients suffering from severe acute respiratory distress syndrome (ARDS) may reduce their vitamin D levels. Many observational studies have shown associations between poor outcomes and low vitamin D levels in critically ill patients. This retrospective study primarily aimed to investigate the time-dependent changes in vitamin D levels and the correlation of vitamin D levels with disease severity and inflammatory markers in patients suffering from ARDS receiving ECMO therapy. Materials and Methods: This study used a longitudinal approach to assess the serial changes and the correlations of vitamin D levels (25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D)) with disease severity and inflammatory markers in 24 invasively mechanically ventilated (IMV) patients treated using ECMO over a period of 17 days. Most of the patients in this study were suffering from severe coronavirus disease 2019 (COVID-19) (n = 19; 79%). Serial blood samples collected during routine blood draws were retrospectively analyzed to assess the dynamics of their vitamin D levels over 17 days of ICU therapy. Results: Hypovitaminosis D (25(OH)D ≤ 50 nmol/L) was prevalent in 18 (75%) patients, while values of 25(OH)D lower than 30 nmol/L were measured in 5 patients (21%), indicating severe deficiency. Additionally, 1,25(OH)2D showed a significant decrease within the first 11 days of intensive care unit (ICU) treatment (these levels dropped by 28%; p = 0.03) and then remained at similar levels throughout the observational period; 25(OH)D levels remained largely unchanged during the observation period. We observed that 25(OH)D showed a significant negative correlation with C-reactive protein (CRP) (p = 0.04), and that 25(OH)D and 1,25(OH)2D levels did not show correlations with disease severity. Conclusions: Patients suffering from severe COVID-19 ARDS showed a significant decrease in their 1,25(OH)2D levels from day 0 to day 11 in the ICU. Therefore, routine vitamin D substitution and monitoring in critically ill patients, especially for patients suffering from ARDS treated with ECMO, should be carried out to prevent hypovitaminosis D. In addition, vitamin D may be associated with inflammation. Further studies are necessary to elucidate the mechanisms behind these retrospective observations. Full article
(This article belongs to the Special Issue Intensive Care and Life Support)
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13 pages, 821 KiB  
Article
Vitamin D Serum Levels and the Development of Intensive Care Unit-Acquired Weakness: Insights from a COVID-19 Intensive Care Cohort
by Jelena Gulišija, Vesna Čapkun, Stefan Golic and Sanda Stojanović Stipić
Pathophysiology 2025, 32(2), 21; https://doi.org/10.3390/pathophysiology32020021 - 9 May 2025
Viewed by 637
Abstract
Background/Objectives: The pathogenesis of intensive care unit-acquired weakness (ICU-AW) is multi-factorial, with some of the main risk factors being sepsis, multiorgan failure, and the inflammatory response related to critical illness. Vitamin D is crucial for muscle function, the immune response, and inflammation, [...] Read more.
Background/Objectives: The pathogenesis of intensive care unit-acquired weakness (ICU-AW) is multi-factorial, with some of the main risk factors being sepsis, multiorgan failure, and the inflammatory response related to critical illness. Vitamin D is crucial for muscle function, the immune response, and inflammation, and has been identified as a predictor of negative outcomes in intensive care unit (ICU) patients with COVID-19. The objective of this preliminary study was to examine the relationship between vitamin D serum levels and the incidence of ICU-AW in a cohort from the University Hospital of Split. Methods: A prospective observational cohort study was conducted in the University Hospital of Split in ICU from December 2021 to March 2022. The inclusion criteria were as follows: patients over 18 years old who had a confirmed severe acute respiratory coronavirus disease 2 (SARS-CoV-2) infection, patients who were mechanically ventilated for more than 48 h, and patients who were weaned from a ventilator over at least 24 h. The exclusion criteria were a history of neurological or musculoskeletal disorders and a pre-existing poor functional status. Vitamin D was detected in the first routine blood sample. Results: A total of 77 patients were observed, with 36 patients who were successfully weaned from a ventilator over at least 24 h and 1 patient who could not be examined because of impaired consciousness (this patient was excluded from further analysis), and thus a total of 35 patients were analyzed. Of these 35 patients, 12 (34%) developed ICU-AW. The median vitamin D serum level in the ICU-AW group was 17 (7.5–73.3), while that in the non-ICU-AW group was 25.2 (12.3–121). The difference in vitamin D serum levels between the groups was not significantly different from zero (p = 0.567). All patients, except for one, were vitamin D insufficient. Conclusions: Vitamin D serum levels in the ICU-AW group were not statistically different from the non-ICU-AW group, possibly due to the small sample size. Given the known roles of vitamin D in muscle function, immune modulation, and inflammation, a potential etiopathogenetic role in ICU-AW cannot be excluded without additional studies. Therefore, further studies with larger sample sizes than ours are necessary to determine whether vitamin D deficiency contributes to the development of ICU-AW and whether supplementation could have preventive or therapeutic value. Full article
(This article belongs to the Section Systemic Pathophysiology)
13 pages, 1705 KiB  
Article
Prognostic Value of Erythrogram Indicators and C-Reactive Protein Levels in Predicting Outcomes of Patients with Coronavirus Disease 2019
by Maria Eduarda Andretta, Matias Nunes Frizzo, Pauline Brendler Goettems-Fiorin, Thiago Gomes Heck, Lucas Machado Sulzbacher, Maicon Machado Sulzbacher, Mirna Stela Ludwig, Gaia Favero, Rita Rezzani and Vitor Antunes de Oliveira
Int. J. Mol. Sci. 2025, 26(9), 4135; https://doi.org/10.3390/ijms26094135 - 27 Apr 2025
Viewed by 509
Abstract
Coronavirus disease 2019 (COVID-19) has posed unprecedented challenges to global public health, highlighting the importance of prognostic biomarkers in critically ill patients. The oxidative stress developed in COVID-19 is associated with impairment in various human organs and systems, and it is related to [...] Read more.
Coronavirus disease 2019 (COVID-19) has posed unprecedented challenges to global public health, highlighting the importance of prognostic biomarkers in critically ill patients. The oxidative stress developed in COVID-19 is associated with impairment in various human organs and systems, and it is related to erythrocyte injury, leading to an elevation in red cell distribution width (RDW) and systemic inflammation. This study aims to assess the prognostic value of erythrogram indicators and C-reactive protein (CRP) levels in 91 intensive care unit-admitted COVID-19 patients, categorized into survivor patients (discharge group) and non-survivor patients (death group). The results were presented using descriptive statistics and the Mann–Whitney test. The most severe cases of respiratory failure in which the patients did not survive showed higher red cell distribution width (RDW) and lower values of red blood cell count, hemoglobin, and hematocrit. RDW may be an important indicator of mortality, as demonstrated by the receiver operating characteristic (ROC) curve analysis. Furthermore, this increase in RDW is correlated with elevated CRP levels, another important clinical outcome for these patients. In conclusion, elevated RDW and CRP levels at admission may be reliable predictors of unfavorable outcomes, emphasizing the utility of these indicators in clinical assessments of COVID-19 patients. Full article
(This article belongs to the Special Issue Molecular Research and Insights into COVID-19: 2nd Edition)
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10 pages, 832 KiB  
Article
The Relation of Angiotensin-Converting Enzyme 2, Renin-Angiotensin-Aldosterone System Inhibitors, and Arterial Stiffness in Acute COVID-19 Emergency Department Patients—A Prospective Observational Study
by Sebastian Schnaubelt, Anna Jakobljevich, Roman Brock, Julia Oppenauer, Andrea Kornfehl, Felix Eibensteiner, Christoph Veigl, Thomas Perkmann, Helmuth Haslacher, Robert Strassl, Roman Reindl-Schwaighofer, Oliver Schlager and Patrick Sulzgruber
J. Clin. Med. 2025, 14(7), 2233; https://doi.org/10.3390/jcm14072233 - 25 Mar 2025
Viewed by 604
Abstract
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) can damage the endothelium and increase arterial stiffness, potentially leading to adverse cardiovascular events. In parallel, systemic inflammation in COVID-19 also impacts endothelial function. Angiotensin-converting enzyme 2 (ACE2) promotes [...] Read more.
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) can damage the endothelium and increase arterial stiffness, potentially leading to adverse cardiovascular events. In parallel, systemic inflammation in COVID-19 also impacts endothelial function. Angiotensin-converting enzyme 2 (ACE2) promotes vasodilation and anti-inflammatory effects, but also facilitates SARS-CoV-2 entry into human cells. Thus, concerns have been raised about the use of RAAS inhibitors (RAASi) in COVID-19 patients due to potential ACE2 upregulation. However, the clinical significance of increased plasma ACE2 (sACE2) in RAASi-treated COVID-19 patients remains unclear. Methods: This prospective, single-centre study evaluated RAASi, sACE2, and vascular function in acutely ill patients with COVID-19 in comparison with acutely ill patients without COVID-19. Adult emergency department patients with confirmed or suspected COVID-19 were enrolled and underwent pulse wave velocity, ankle brachial index, and sACE2 measurements. Results: In the 152 included patients (50% female, median age 62 years, 68% COVID-19 positive), the sACE2 values were slightly higher in the COVID-19 (0.485 [0.364–1.329]) than in the non-COVID-19 subgroup (0.458 [0.356–1.138]; p = 0.70). No significant differences in sACE2 were observed between patients with and without RAASi, regardless of COVID-19 status. Pulse wave velocity values differed significantly between groups (p = 0.015). Conclusions: In emergency department patients, sACE2 was upregulated in COVID-19 patients, probably due to oxidative stress and inflammation. RAASi did not increase sACE2, but may have protective effects against inflammation. Elevated sACE2 appeared to have a beneficial effect on arterial stiffness in all patients. These findings support continued RAASi therapy in COVID-19 patients to protect against chronic inflammation and apoptosis. Full article
(This article belongs to the Section Vascular Medicine)
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14 pages, 226 KiB  
Article
Risk Factors Affecting the Severity, Mortality, and Intensive Care Unit Admission of COVID-19 Patients: A Series of 1075 Cases
by Ecem Narin Çopur, Dilek Ergün, Recai Ergün, Serap Atik, Hatice Türk Dağı and Muslu Kazım Körez
Viruses 2025, 17(3), 429; https://doi.org/10.3390/v17030429 - 17 Mar 2025
Viewed by 860
Abstract
Background: The clinical spectrum of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is broad; it can range from asymptomatic cases to mild upper respiratory tract illness, respiratory failure, and severe multiorgan failure resulting in death. Therefore, it is important to identify the [...] Read more.
Background: The clinical spectrum of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is broad; it can range from asymptomatic cases to mild upper respiratory tract illness, respiratory failure, and severe multiorgan failure resulting in death. Therefore, it is important to identify the clinical course of the disease and the factors associated with mortality. Objective: The aim of this study is to identify the risk factors associated with the severity of the disease, intensive care unit admission, and mortality in COVID-19 patients. Methods: A total of 1075 patients with clinical and radiological findings compatible with COVID-19 pneumonia and positive SARS-CoV-2 PCR were selected and retrospectively screened. All included patients were classified according to the 7th edition of the 2019 Coronavirus Disease Guidelines published by the National Health Commission of China. Results: It was observed that elevated white blood count (WBC) increased the severity of COVID-19 by 3.26 times and the risk of intensive care unit (ICU) admission by 3.47 times. Patients with high D-dimer levels had a 91% increased risk, and those with high fibrinogen levels had a 2.08 times higher risk of severe disease. High C-reactive protein (CRP) values were found to increase disease severity by 6.89 times, mortality by 12.84 times, and ICU admission by 3.37 times. Conclusions: Identifying the factors associated with disease severity, ICU admission, and mortality in COVID-19 patients could help reduce disability and mortality rates in pandemics. Full article
(This article belongs to the Special Issue COVID-19 and Pneumonia, 3rd Edition)
8 pages, 465 KiB  
Article
Cytomegalovirus Blood DNAemia in Patients with Severe SARS-CoV-2 Pneumonia
by Jean-Baptiste Mesland, Christine Collienne, Virginie Montiel, Alexis Werion, Philippe Hantson, Xavier Wittebole, Pierre-François Laterre and Ludovic Gerard
Infect. Dis. Rep. 2025, 17(1), 8; https://doi.org/10.3390/idr17010008 - 26 Jan 2025
Cited by 1 | Viewed by 853
Abstract
Introduction: Cytomegalovirus (CMV) DNAemia has been described in critically ill patients, including patients with severe acute respiratory syndrome-coronavirus2 (SARS-CoV-2) infection. Our objective is to evaluate the prevalence and clinical impact of CMV DNAemia among patients undergoing invasive mechanical ventilation (IMV) for severe SARS-CoV-2 [...] Read more.
Introduction: Cytomegalovirus (CMV) DNAemia has been described in critically ill patients, including patients with severe acute respiratory syndrome-coronavirus2 (SARS-CoV-2) infection. Our objective is to evaluate the prevalence and clinical impact of CMV DNAemia among patients undergoing invasive mechanical ventilation (IMV) for severe SARS-CoV-2 infection and to explore the association between CMV DNAemia levels and clinical outcomes. Methods: In this retrospective monocentric study, we included patients admitted in a tertiary ICU for severe COVID-19 and who required IMV. We aimed to compare clinical and demographic variables between patients with and without CMV DNAemia. Univariate and Cox regression analyses were performed to identify factors associated with CMV DNAemia. Results: During the study period, CMV blood DNAemia occurred in 30/135 patients (22%). Patients with CMV blood DNAemia had longer ICU and hospital length of stay, as well as longer duration of IMV, and were more likely to have received dexamethasone. However, there was no significant difference in ICU mortality between patients with and without CMV DNAemia (64.8% vs. 56.7%, p = 0.42). The Cox regression analysis showed that dexamethasone was the only factor independently associated with CMV blood DNAemia (HR 4.23 [1.006–17.792], p = 0.049). Conclusions: In patients with severe SARS-CoV-2 pneumonia requiring IMV, CMV DNAemia is common and associated with prolonged ventilation and increased LOS but not with increased mortality. Full article
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11 pages, 615 KiB  
Article
Low-Level Zoonotic Transmission of Clade C MERS-CoV in Africa: Insights from Scoping Review and Cohort Studies in Hospital and Community Settings
by Andrew Karani, Cynthia Ombok, Silvia Situma, Robert Breiman, Marianne Mureithi, Walter Jaoko, M. Kariuki Njenga and Isaac Ngere
Viruses 2025, 17(1), 125; https://doi.org/10.3390/v17010125 - 17 Jan 2025
Cited by 1 | Viewed by 1527
Abstract
Human outbreaks of Middle East respiratory syndrome coronavirus (MERS-CoV) are more common in Middle Eastern and Asian human populations, associated with clades A and B. In Africa, where clade C is dominant in camels, human cases are minimal. We reviewed 16 studies (n [...] Read more.
Human outbreaks of Middle East respiratory syndrome coronavirus (MERS-CoV) are more common in Middle Eastern and Asian human populations, associated with clades A and B. In Africa, where clade C is dominant in camels, human cases are minimal. We reviewed 16 studies (n = 6198) published across seven African countries between 2012 and 2024 to assess human MERS-CoV cases. We also analyzed data from four cohort studies conducted in camel-keeping communities between 2018 and 2024 involving camel keepers, camel slaughterhouse workers, and hospital patients with acute respiratory illness (ARI). The analysis showed a pooled MERS-CoV prevalence of 2.4% (IQR: 0.6, 11.4) from 16 publications and 1.14% from 4 cohort studies (n = 2353). Symptomatic cases were rarely reported, with most individuals reporting camel contact, and only 12% had travel history to the Middle East. There was one travel-associated reported death, resulting in a mortality rate of 0.013%. The findings suggest a low camel-to-human transmission of clade C MERS-CoV in Africa. Ongoing research focuses on genomic comparisons between clade C and the more virulent clades A and B, alongside the surveillance of viral evolution. This study highlights the need for continuous monitoring but indicates that MERS-CoV clade C currently poses a minimal public health threat in Africa. Full article
(This article belongs to the Section Coronaviruses)
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9 pages, 1064 KiB  
Communication
Comparative Analysis of Viral Load Quantification Using Reverse Transcription Polymerase Chain Reaction and Digital Droplet Polymerase Chain Reaction
by Paula Gebe Abreu Cabral, Sávio Bastos de Souza, Raul Ferraz Arruda, Sheila Passos de Figueiredo Cabral, Arícia Leone Evangelista Monteiro de Assis, Yolanda Porto Muniz Martins, Antônio Brazil Viana Junior, Junbiao Chang, Pingsheng Lei and Renato Martins da Silva
Int. J. Mol. Sci. 2025, 26(2), 725; https://doi.org/10.3390/ijms26020725 - 16 Jan 2025
Viewed by 1460
Abstract
In the year 2019, a highly virulent coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, precipitating the outbreak of the illness known as coronavirus disease 2019 (COVID-19). The commonly employed reverse transcription polymerase chain reaction (RT-qPCR) methodology serves to estimate the [...] Read more.
In the year 2019, a highly virulent coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, precipitating the outbreak of the illness known as coronavirus disease 2019 (COVID-19). The commonly employed reverse transcription polymerase chain reaction (RT-qPCR) methodology serves to estimate the viral load in each patient’s sample by employing a standard curve. However, it is imperative to recognize that this technique exhibits limitations with respect to clinical diagnosis and therapeutic applications, since an advancement of the conventional polymerase chain reaction methods, digital polymerase chain reaction (digital PCR or DDPCR), enables the direct quantification and clonal amplification of nucleic acid strands. The primary divergence between dPCR and traditional PCR resides in their approaches to measuring nucleic acid quantities. In this study, we investigated the viral loads of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) within 461 participants. By employing both RT-qPCR and DDPCR techniques, we established a comparison between the quantification methodologies of the two approaches. Our findings illustrate that the quantification through DDPCR affords a superior means of monitoring viral load within lower respiratory tract samples, thus enhancing the assessment of disease progression, particularly in scenarios characterized by low viral loads. Full article
(This article belongs to the Special Issue Molecular Research on Antiviral Mechanism)
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18 pages, 3272 KiB  
Article
Plant-Based Antigen Production Strategy for SARS-CoV-2 Nucleoprotein and RBD and Its Application for Detection of Antibody Responses in COVID-19 Patients
by Katerina Takova, Valeria Tonova, Ivan Minkov, Eugenia S. Mardanova, Nikolai V. Ravin, Stanislav Kotsev, Maria Pishmisheva and Gergana Zahmanova
Appl. Sci. 2025, 15(2), 786; https://doi.org/10.3390/app15020786 - 15 Jan 2025
Cited by 1 | Viewed by 2369
Abstract
During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the development of efficient serological tests for monitoring the dynamics of the disease as well as the immune response after illness or vaccination was critical. In this regard, low-cost and fast production of [...] Read more.
During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the development of efficient serological tests for monitoring the dynamics of the disease as well as the immune response after illness or vaccination was critical. In this regard, low-cost and fast production of immunogenic antigens is essential for the rapid development of diagnostic serological kits. This study assessed the plant-based production of nucleoprotein (N) of SARS-CoV-2 and chimeric receptor-binding domain (RBD) of SARS-CoV-2 presented by hepatitis E virus capsid (HEV/RBD) and validation of the plant-derived proteins as diagnostic antigens for serological tests. The target proteins were expressed in and purified from Nicotiana benthamiana plants. The resulting yield of chimeric HEV/RBD protein reached 100 mg/kg fresh weight and 30 mg/kg fresh weight for N protein. The purified N protein and HEV/RBD protein were used to develop an indirect enzyme-linked immunosorbent assay (iELISA) for the detection of antibodies to SARS-CoV-2 in human sera. To validate the iELISA tests, a panel of 84 sera from patients diagnosed with COVID-19 was used, and the results were compared to those obtained by another commercially available ELISA kit (Dia.Pro D. B., Sesto San Giovanni, Italy). The performance of an HEV/RBD in-house ELISA showed a sensitivity of 89.58% (95% Cl: 75.23–95.37) and a specificity of 94.44% (95% Cl: 76.94–98.2). Double Recognition iELISA based on HEV/RBD and N protein is characterized by a lower sensitivity of 85.42% (95% Cl: 72.24–93.93) and specificity of 94.44% (95% Cl: 81.34–99.32) at cut-off = 0.154, compared with iELISA based on HEV/RBD. Our study confirms that N and fusion HEV/RBD proteins, which are transiently expressed in plants, can be used to detect responses to SARS-CoV-2 in human sera reliably. Our research validates the commercial potential of using plants as an expression system for recombinant protein production and their application as diagnostic reagents for serological detection of infectious diseases, hence lowering the cost of diagnostic kits. Full article
(This article belongs to the Section Chemical and Molecular Sciences)
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18 pages, 9812 KiB  
Article
Newcastle Disease Virus Displaying an Ectodomain of Middle East Respiratory Syndrome Coronavirus Spike Protein Elicited Robust Humoral and Cellular Immunity in Mice
by Jaturawitt Prasopsiri, Kanjana Srisutthisamphan, Benjamas Liwnaree, Juggragarn Jengarn, Jarin Kramyu, Payuda Hansoongnern, Papon Muangsanit, Nathiphat Tanwattana, Challika Kaewborisuth, Suttipun Sungsuwan, Anan Jongkaewwattana and Nanchaya Wanasen
Vaccines 2025, 13(1), 2; https://doi.org/10.3390/vaccines13010002 - 24 Dec 2024
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Abstract
Background: Middle East Respiratory Syndrome Coronavirus (MERS-CoV) causes severe respiratory illness in humans and currently lacks an approved vaccine. The Newcastle disease virus (NDV) vector is a well-established, safe, and effective platform for vaccine development. With recent advancements in stabilizing coronavirus spike proteins [...] Read more.
Background: Middle East Respiratory Syndrome Coronavirus (MERS-CoV) causes severe respiratory illness in humans and currently lacks an approved vaccine. The Newcastle disease virus (NDV) vector is a well-established, safe, and effective platform for vaccine development. With recent advancements in stabilizing coronavirus spike proteins to enhance their antigenicity, this study aimed to determine whether modifications to the MERS-CoV spike protein could improve its presentation on NDV particles, allowing the resulting virus to be used as an inactivated vaccine. Methods: We codon-optimized the gene encoding the ectodomain of the MERS-CoV spike protein and incorporated modifications at the S1/S2 and S2’ cleavage sites, along with a proline substitution at residues V1060-L1061. This modified spike gene was inserted into the NDV genome to create the NDV-SMERS virus. After purification and inactivation, the vaccine’s immunogenicity was assessed in mice. Results: Mice immunized with the inactivated NDV-SMERS vaccine developed robust anti-spike IgGs, neutralizing antibodies, and cellular immune responses. The study demonstrated that modifications to the MERS-CoV spike protein were essential for its effective presentation on NDV particles. Additionally, the spike gene insert remained stable through five egg passages, confirming the vector’s stability. Conclusions: Engineering the MERS-CoV spike protein is crucial for its successful display on NDV particles. The strong immune responses elicited by the NDV-SMERS vaccine in mice highlight that NDV is a promising, safe, and effective platform for MERS-CoV vaccination. Full article
(This article belongs to the Section Vaccine Design, Development, and Delivery)
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28 pages, 5658 KiB  
Review
Mechanistic Insights into the Mutational Landscape of the Main Protease/3CLPro and Its Impact on Long-Term COVID-19/SARS-CoV-2 Management
by Aganze Gloire-Aimé Mushebenge, Samuel Chima Ugbaja, Nonjabulo Ntombikhona Magwaza, Nonkululeko Avril Mbatha, Tambwe Willy Muzumbukilwa, Mukanda Gedeon Kadima, Fave Yohanna Tata, Mthokosizi Bongani Nxumalo, Riziki Ghislain Manimani, Ntabaza Ndage, Bakari Salvius Amuri, Kahumba Byanga, Manimbulu Nlooto, Rene B. Khan and Hezekiel M. Kumalo
Future Pharmacol. 2024, 4(4), 825-852; https://doi.org/10.3390/futurepharmacol4040044 - 28 Nov 2024
Viewed by 2757
Abstract
The main proteinase (Mpro), or 3CLpro, is a critical enzyme in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lifecycle and is responsible for breaking down and releasing vital functional viral proteins crucial for virus development and transmission. As a catalytically active dimer, [...] Read more.
The main proteinase (Mpro), or 3CLpro, is a critical enzyme in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lifecycle and is responsible for breaking down and releasing vital functional viral proteins crucial for virus development and transmission. As a catalytically active dimer, its dimerization interface has become an attractive target for antiviral drug development. Recent research has extensively investigated the enzymatic activity of Mpro, focusing on its role in regulating the coronavirus replication complex and its significance in virus maturation and infectivity. Computational investigations have identified four druggable pockets, suggesting potential allosteric sites beyond the substrate-binding region. Empirical validation through site-directed alanine mutagenesis has targeted residues in both the active and allosteric regions and corroborated these predictions. Structural studies of drug target proteins can inform therapeutic approaches, with metadynamics simulations shedding light on the role of H163 in regulating Mpro function and providing insights into its dynamic equilibrium to the wild-type enzyme. Despite the efficacy of vaccines and drugs in mitigating SARS-CoV-2 spread, its ongoing viral evolution, selective pressures, and continued transmission pose challenges, potentially leading to resistant mutations. Phylogenetic analyses have indicated the existence of several resistant variations predating drug introduction to the human population, emphasizing the likelihood of drug spread. Hydrogen/deuterium-exchange mass spectrometry reveals the structural influence of the mutation. At the same time, clinical trials on 3CLPro inhibitors underscore the clinical significance of reduced enzymatic activity and offer avenues for future therapeutic exploration. Understanding the implications of 3CLPro mutations holds promise for shaping forthcoming therapeutic strategies against COVID-19. This review delves into factors influencing mutation rates and identifies areas warranting further investigation, providing a comprehensive overview of Mpro mutations, categorization, and terminology. Moreover, we examine their associations with clinical outcomes, illness severity, unresolved issues, and future research prospects, including their impact on vaccine efficacy and potential therapeutic targeting. Full article
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