Variability in the Clinical Course of COVID-19 in a Retrospective Analysis of a Large Real-World Database

External validation of two clinical prediction models for mortality in COVID-19 patients (4C and NEWS2), in three centers in Medellín, Colombia: Assessing the impact of vaccination over time

OBJECTIVES

External validation of the 4C and NEWS2 scores for the prediction of in-hospital mortality in COVID-19 patients, and evaluation of its operational performance in two time periods: before and after the start of the vaccination program in Colombia.

METHODS

Retrospective cohort in three high complexity hospitals in the city of Medellín, Colombia, between June 2020 and April 2022.

RESULTS

The areas under the ROC curve (AUC) for the 4C mortality risk score and the NEWS2 were 0.75 (95% CI 0.73-0.78) and 0.68 (95% CI 0.66-0.71), respectively. For the 4C score, the AUC for the first and second periods was 0.77 (95% CI 0.74-0.80) and 0.75 (95% CI 0.71-0.78); whilst for the NEWS2 score, it was 0.68 (95% CI 0.65-0.71) and 0.69 (95% CI 0.64-0.73). The calibration for both scores was adequate, albeit with reduced performance during the second period.

CONCLUSIONS

The 4C mortality risk score proved to be the more adequate predictor of in-hospital mortality in COVID-19 patients in this Latin American population. The operational performance during both time periods remained similar, which shows its utility notwithstanding major changes, including vaccination, as the pandemic evolved.

Viral respiratory infections and air pollution: A review focused on research in Poland

The COVID-19 pandemic has reinforced an interest in the relationship between air pollution and respiratory viral infections, indicating that their burden can be increased under poor air quality. This paper reviews the pathways through which air pollutants can enhance susceptibility to such infections and aggravate their clinical course and outcome. It also summarizes the research exploring the links between various viral infections and exposure to solid and gaseous pollution in Poland, a region characterized by poor air quality, especially during a heating season. The majority of studies focused on concentrations of particulate matter (PM; 86.7%); the other pollutants, i.e., BaP, benzene, CO, NOx, O3, and SO2, were studied less often and sometimes only in the context of a particular infection type. Most research concerned COVID-19, showing that elevated levels of PM and NO2 correlated with higher morbidity and mortality, while increased PM2.5 and benzo[a]pyrene levels were related to worse clinical course and outcome in hospitalized, regardless of age and dominant SARS-CoV-2 variant. PM10 and PM2.5 levels were also associated with the incidence of influenza-like illness and, along with NO2 concentrations, with a higher rate of children's hospitalizations due to lower respiratory tract RSV infections. Higher levels of air pollutants also increased hospitalization due to bronchitis (PM, NOx, and O3) and emergency department admission due to viral croup (PM10, PM2.5, NOx, CO, and benzene). Although the conducted studies imply only correlations and have other limitations, as discussed in the present paper, it appears that improving air quality through reducing combustion processes in energy production in Poland should be perceived as a part of multilayered protection measures against respiratory viral infections, decreasing the healthcare costs of COVID-19, lower tract RSV infections, influenza, and other respiratory viral diseases prevalent between autumn and early spring, in addition to other health and climate benefits.

Cardiovascular complications in the course of COVID-19 - lessons learned and implications for the future care of patients with viral respiratory diseases: Data from a single center retrospective observational study

BACKGROUND

Factors associated with cardiovascular complications of COVID-19 remain understudied.

OBJECTIVES

Here we investigate the occurrence and risk factors of arrythmias, myocardial infarction and/or stroke, and thromboembolism in the course of COVID-19.

METHODS

We have performed an observational study with prospectively designed data collection. Data of patients diagnosed with COVID-19 who were admitted from March 6th 2020 to November 30th 2021 in our Hospital were analyzed. Logistic regression was used to identify variables associated with the odds of early hospital death due to COVID-19.

RESULTS

Fourteen-point three percent of 1964 patients had cardiovascular complications, 6.36 % arrhythmias, 5.5 % thromboembolic events and 2.39 % myocardial infarction and/or stroke. Factors independently increasing the odds of arrhythmia were older age (OR=1.49 [95 % CI: 1.17-1.92], p = 0.02), longer time between admission and the first onset of symptoms (1.02 [0.99-1.05], p = 0.049), concomitant atrial fibrillation/flutter (2.84 [1.37-5.70], p = 0.004), nicotinism (2.49 [1.37-4.49], p = 0.002), and eGFR<60 ml/min/1.73m2 (2.44 [1.08-5.59], p = 0.033). Factors independently increasing the odds of myocardial infarction and/or stroke were dementia (4.55 [0.97-19.3], p = 0.044), hemiplegia (12.67 [3.12-46.1], p < 0.001), nicotinism (3.36 [1.30-10.4], p = 0.013) and higher C-reactive protein concentration (1.01 [1.00-1.01], p = 0.040). Factors independently increasing the odds of thromboembolic events were longer hospitalization (1.08 [1.05-1.10], p < 0.001) and higher d-dimers (1.04 [1.02-1.05], <0.001).

CONCLUSIONS

The risk of cardiovascular complications was especially pronounced in patients with older age, pre-existing cardiovascular disease and more sever pneumonia at presentation to care. This underlines the importance of close and careful clinical follow-up in the course of COVID-19 for specific patients' populations, including a pro-active approach in diagnosis.

Complexity and Diversity of the Neurological Spectrum of SARS-CoV-2 over Three Waves of COVID-19

Background/Objectives: SARS-CoV-2 continually mutates, with five identified variants. Many neurological manifestations were observed during the COVID-19 pandemic, with differences between virus variants. The aim of this study is to assess the frequency and characteristics of neurological manifestations during COVID-19 in hospitalized patients over three waves in Poland with comparison and analysis correlation with the course of infection. Methods: This retrospective single-center study included 600 consecutive adults with confirmed COVID-19, hospitalized during 3 waves (pre-Delta, Delta and Omicron) in Poland. Demographic and clinical information and neurological manifestations were collected and compared across three periods. Results: The median age of the study group was 68, lower during the Delta wave. In the Omicron period, the disease severity at admission and inflammatory markers concentration were the lowest. Neurological manifestations were observed in 49%. The most common were altered mentation, headache, myalgia, mood disorder, ischemic stroke and encephalopathy. Smell and taste disturbances (STDs) were less frequent in the Omicron period. Neurological complications were predominant in the pre-Delta and Omicron periods. Ischemic stroke was observed more often in pre-Delta period. Altered mentation was related to higher severity at admission, worse lab test results, higher admission to ICU and mortality, while headache reduced mortality. Pre-existing dementia was related to higher mortality. Conclusions: Neurological manifestations of COVID-19 are frequent, with a lower rate of STDs in the Omicron period and more often cerebrovascular diseases in the pre-Delta period. Headache improves the course of COVID-19, while altered mentation, stroke and neurological comorbidities increase severity and mortality.

Clinico-Virological Outcomes and Mutational Profile of SARS-CoV-2 in Adults Treated with Ribavirin Aerosol for COVID-19 Pneumonia

The emergence of new SARS-CoV-2 variants can affect vaccine efficacy, laboratory diagnosis and the therapies already available, triggering interest in the search for antiviral agents for SARS-CoV-2 infections. Ribavirin (RBV) is a broad-spectrum antiviral with demonstrated in vitro activity against multiple viruses, including SARS-CoV-2. This retrospective study evaluated the dynamics and viral clearance of SARS-CoV-2 in hospitalised adult participants (PTs) with COVID-19 pneumonia who received an RBV aerosol within a compassionate use study. The impact of RBV on the clinical outcome and the mutational profile of SARS-CoV-2 was also assessed. The median RNA values measured in nine PTs included in this study decreased from baseline to discharge (at BL, threshold cycle (Ct) = 22.4, IQR 19.84-5.07; at discharge, Ct = 27.92, IQR 26.43-36.11), with a significant decline in the Ct value evaluated by Friedman rank ANOVA analysis, p = 0.032. Seven out of nine PTs experienced a clinical improvement, while two PTs deceased during hospitalisation. In PTs with a favourable outcome, the virus clearance rate at discharge was 28.6%. The cumulative clearance rate was 71.4% within 14 days from discharge. A mutational pattern after RBV was detected in three out of five PTs in whom whole-genome sequencing was available. Our findings suggest that RBV limits SARS-CoV-2 replication, possibly resulting in a favourable clinical outcome. Ribavirin may also contribute to the mutational spectrum of SARS-CoV-2.

In Silico Analyses Indicate a Lower Potency for Dimerization of TLR4/MD-2 as the Reason for the Lower Pathogenicity of Omicron Compared to Wild-Type Virus and Earlier SARS-CoV-2 Variants

The SARS-CoV-2 Omicron variants have replaced all earlier variants, due to increased infectivity and effective evasion from infection- and vaccination-induced neutralizing antibodies. Compared to earlier variants of concern (VoCs), the Omicron variants show high TMPRSS2-independent replication in the upper airway organs, but lower replication in the lungs and lower mortality rates. The shift in cellular tropism and towards lower pathogenicity of Omicron was hypothesized to correlate with a lower toll-like receptor (TLR) activation, although the underlying molecular mechanisms remained undefined. In silico analyses presented here indicate that the Omicron spike protein has a lower potency to induce dimerization of TLR4/MD-2 compared to wild type virus despite a comparable binding activity to TLR4. A model illustrating the molecular consequences of the different potencies of the Omicron spike protein vs. wild-type spike protein for TLR4 activation is presented. Further analyses indicate a clear tendency for decreasing TLR4 dimerization potential during SARS-CoV-2 evolution via Alpha to Gamma to Delta to Omicron variants.

The burden of infectious diseases throughout and after the COVID-19 pandemic (2020-2023) and Russo-Ukrainian war migration

Understanding how the infectious disease burden was affected throughout the COVID-19 pandemic is pivotal to identifying potential hot spots and guiding future mitigation measures. Therefore, our study aimed to analyze the changes in the rate of new cases of Poland's most frequent infectious diseases during the entire COVID-19 pandemic and after the influx of war refugees from Ukraine. We performed a registry-based population-wide study in Poland to analyze the changes in the rate of 24 infectious disease cases from 2020 to 2023 and compared them to the prepandemic period (2016-2019). Data were collected from publicly archived datasets of the Epimeld database published by national epidemiological authority institutions. The rate of most of the studied diseases (66.6%) revealed significantly negative correlations with the rate of SARS-CoV-2 infections. For the majority of infectious diseases, it substantially decreased in 2020 (in case of 83%) and 2021 (63%), following which it mostly rebounded to the prepandemic levels and, in some cases, exceeded them in 2023 when the exceptionally high annual rates of new cases of scarlet fever, Streptococcus pneumoniae infections, HIV infections, syphilis, gonococcal infections, and tick-borne encephalitis were noted. The rate of Clostridioides difficile enterocolitis was two-fold higher than before the pandemic from 2021 onward. The rate of Legionnaires' disease in 2023 also exceeded the prepandemic threshold, although this was due to a local outbreak unrelated to lifted COVID-19 pandemic restrictions or migration of war refugees. The influx of war migrants from Ukraine could impact the epidemiology of sexually transmitted diseases. The present analysis indicates that continued efforts are needed to prevent COVID-19 from overwhelming healthcare systems again and decreasing the control over the burden of other infectious diseases. It also identifies the potential tipping points that require additional mitigation measures, which are also discussed in the paper, to avoid escalation in the future.

Outcomes of COVID-19 Omicron variant in patients with rheumatoid arthritis: a nationwide Greek cohort study

OBJECTIVES

Patients with RA were at increased risk for COVID-19-associated hospitalization and death during the first year of the pandemic in Greece. We aimed to examine their outcomes after the SARS-Cov-2 Omicron, a more contagious but with milder clinical impacts variant, prevailed.

METHODS

A retrospective, nationwide study was conducted between 1 January 2022 and 30 June 2022 in all RA patients under treatment and matched (1:5) on age, sex and region of domicile random general population comparators. Confirmed SARS-CoV-2 infections, hospitalizations and deaths, anti-rheumatic medications, prior COVID-19, vaccinations and anti-viral medications were recorded.

RESULTS

Among 34 182 RA patients, infections (n = 5569, 16.29%), hospitalizations (n = 489, 1.43%) and deaths (n = 106, 0.31%) were more frequent than among comparators. Incidence rates per 1000 person/years of infection [IRR (95% CI):1.19 (1.16, 1.23)], hospitalization [IRR (95% CI):2.0 (1.82, 2.24)], and death [IRR (95% CI):1.81 (1.44, 2.27)] were increased in RA despite better vaccination coverage (89% vs 84%) and more frequent use of anti-viral medications (2.37% vs 1.08). Logistic regression analysis after correcting for age, sex, vaccinations, prior COVID-19, and anti-viral medications in SARS-CoV-2 infected RA patients and comparators revealed increased risk of hospitalization (OR: 2.02, 95% CI: 1.79, 2.27) and death [OR: 1.73, (95% CI: 1.36, 2.20)] in RA. Among infected RA patients, rituximab treatment conferred increased risks for hospitalization [OR: 6.12, (95% CI: 2.89, 12.92)] and death [OR: 12.06 (95% CI: 3.90, 37.31)], while JAK inhibitors increased only hospitalization risk [OR: 2.18 (95% CI: 1.56, 3.06)].

CONCLUSION

RA remains a risk factor for hospitalization and death in an era of a relatively low COVID-19 fatality rate, pointing to the need of perseverance in vaccination programs and wider use of anti-viral medications.

Trends of Hepatitis A Virus Infection in Poland: Assessing the Potential Impact of the COVID-19 Pandemic and War in Ukraine

Hepatitis A virus (HAV) is the most common cause of acute viral hepatitis, which is preventable by vaccination. This study analyzed trends of HAV infections in Poland according to socio-demographic features in the years 2009-2022 and assessed the potential impact of the COVID-19 pandemic (2020-2023) and the migration of war refugees from Ukraine (since February 2022). In 2009-2022, 7115 new cases of HAV infection were diagnosed in Poland, especially among men (66.4%) and in urban areas (77.4%). Infections among men were most common at the age of 25-34 (median rate 0.43 per 105) and in women aged 15-24 (median rate 0.39 per 105). Analysis of the 14-year frequency of HAV infections exhibited three trends, regardless of gender, age, and residence. The infections revealed a downward trend in 2009-2014, increased significantly in 2014-2018, and decreased again after 2018. A particularly rapid increase in HAV infections occurred between March 2017 and February 2018 (median rate 0.79 per 105). The high level of new infections persisted until the beginning of the COVID-19 pandemic, at which point it dropped significantly but did not reach the level recorded before March 2017. During the Omicron SARS-CoV-2 dominance period, the median rate of HAV infections was 0.053 per 105, with a four-fold increase being observed from February 2022 (when the migration of war refugees from Ukraine began) to August 2022. The presented results can serve as a reference point for further observations in Central Europe. The HAV epidemiological situation is unlikely to escalate in Poland but requires further monitoring.

COVID-19 prophylaxis, diagnostics, and treatment in patients with rheumatic diseases. The Polish experts panel opinion

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolves, infection management in vulnerable populations requires formalized guidance. Although low-virulence variants of SARS-CoV-2 remain predominant, they pose an increased risk of severe illness in adults with rheumatic and musculoskeletal diseases (RMDs). Several disease-specific (chronic long-grade inflammation, concomitant immunosuppression) and individual (advanced age, multimorbidity, pregnancy, vaccination status) factors contribute to excess risk in RMD populations. Various post-COVID-19 manifestations are also increasingly reported and appear more commonly than in the general population. At a pathogenetic level, complex interplay involving innate and acquired immune dysregulation, viral persistence, and genetic predisposition shapes a unique susceptibility profile. Moreover, incident cases of SARS-CoV-2 infection as a trigger factor for the development of autoimmune conditions have been reported. Vaccination remains a key preventive strategy, and encouraging active education and awareness will be crucial for rheumatologists in the upcoming years. In patients with RMDs, COVID-19 vaccines' benefits outweigh the risks. Derivation of specialized diagnostic and therapeutic protocols within a comprehensive COVID-19 care plan represents an ideal scenario for healthcare system organization. Vigilance for symptoms of infection and rapid diagnosis are key for introducing antiviral treatment in patients with RMDs in a timely manner. This review provides updated guidance on optimal immunization, diagnosis, and antiviral treatment strategies.

Molecular characterization of SARS-CoV-2 Omicron clade and clinical presentation in children

Since its emergence, SARS-CoV-2 Omicron clade has shown a marked degree of variability and different clinical presentation compared with previous clades. Here we demonstrate that at least four Omicron lineages circulated in children since December 2021, and studied until November 2022: BA.1 (33.6%), BA.2 (40.6%), BA.5 (23.7%) and BQ.1 (2.1%). At least 70% of infections concerned children under 1 year, most of them being infected with BA.2 lineages (n = 201, 75.6%). Looking at SARS-CoV-2 genetic variability, 69 SNPs were found to be significantly associated in pairs, (phi <  - 0.3 or > 0.3 and p-value < 0.001). 16 SNPs were involved in 4 distinct clusters (bootstrap > 0.75). One of these clusters (A23040G, A27259C, T23617G, T23620G) was also positively associated with moderate/severe COVID-19 presentation (AOR [95% CI] 2.49 [1.26-4.89] p-value: 0.008) together with comorbidities (AOR [95% CI] 2.67 [1.36-5.24] p-value: 0.004). Overall, these results highlight the extensive SARS-CoV-2 Omicron circulation in children, mostly aged < 1 year, and provide insights on viral diversification even considering low-abundant SNPs, finally suggesting the potential contribution of viral diversification in affecting disease severity.

Clinical features and outcomes in adults with COVID-19 during the pre-Omicron and Omicron waves

OBJECTIVES

We conducted a single-center retrospective study to compare patient characteristics and death rates during the Omicron (O, December 01, 2021, to September 30, 2022) and pre-Omicron (PO, March 01, 1920, to October 31, 2021) periods.

PATIENTS AND METHODS

We retrospectively analyzed the data of 2932 patients (1242 (O) and 1690 (PO)) hospitalized (>24 h) with laboratory-confirmed COVID.

RESULTS

Compared to the PO period, O period patients were less frequently men, had a lower body mass index and fewer comorbidities except for immunosuppression and pregnancy. Nosocomial COVID-19 accounted for 18.2 % (O) and 15.4 % (PO) of cases (p = 0.05). Patient mortality rates during the O and PO periods were 11.0 % and 16.9 % (p < 0.001), respectively. Unvaccinated status (p < 0.001), existence of comorbidities, (p < 0.001) and high LDH value at baseline (p = 0.015), but not the period, were identified as factors likely to explain death.

CONCLUSION

During the Omicron period, the inpatient death rate remained > 10 %, especially among unvaccinated and comorbid patients. Nosocomial cases were more frequent.

Differences in Clinical Presentation of COVID-19 in Children Hospitalized During Domination of Early (BA.1, BA.2) and Late (BA.5, BA.2.75, BQ.1 and XBB.1.5) SARS-CoV-2 Omicron Subvariants

This study analyzed data for 1098 children: 575 diagnosed with COVID-19 between January and June 2022 (early Omicron) and 523 hospitalized from July 2022 to April 2023 (late Omicron). New Omicron subvariants lead to similar recovery rates without deaths and acute respiratory distress syndrome in children as BA.1 and BA.2, however, they more often cause fever and croup. Children suffering from comorbidities, presenting with pulmonary lesions and older, may be prone to a more severe consequences of COVID-19 in terms of the currently dominating Omicron subvariants.

Venous Thromboembolism in Patients Hospitalized for COVID-19 in a Non-Intensive Care Unit

Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) may contribute to venous thromboembolism (VTE) with adverse effects on the course of COVID-19. The purpose of this study was to investigate an incidence and risk factors for VTE in patients hospitalized for COVID-19 in a non-intensive care unit (non-ICU). Consecutive adult patients with COVID-19 hospitalized from November 2021 to March 2022 in the isolation non-ICU at our center were included in the study. Incidence of VTE including pulmonary embolism (PE) and deep vein thrombosis (DVT), clinical characteristics, and D-dimer plasma levels during the hospitalization were retrospectively evaluated. Among the 181 patients (aged 68.8 ± 16.2 years, 44% females, 39% Delta SARS-CoV-2 variant, 61% Omicron SARS-CoV-2 variant), VTE occurred in 29 patients (VTE group, 16% of the entire cohort). Of them, PE and DVT were diagnosed in 15 (8.3% of the entire cohort) and 14 (7.7%) patients, respectively. No significant differences in clinical characteristics were observed between the VTE and non-VTE groups. On admission, median D-dimer was elevated in both groups, more for VTE group (1549 ng/mL in VTE vs. 1111 ng/mL in non-VTE, p = 0.09). Median maximum D-dimer was higher in the VTE than in the non-VTE group (5724 ng/mL vs. 2200 ng/mL, p < 0.005). In the univariate analysis, systemic arterial hypertension and the need for oxygen therapy were predictors of VTE during hospitalization for COVID-19 (odds ratio 2.59 and 2.43, respectively, p < 0.05). No significant associations were found between VTE risk and other analyzed factors; however, VTE was more likely to occur in patients with a history of VTE, neurological disorders, chronic pulmonary or kidney disease, atrial fibrillation, obesity, and Delta variant infection. Thromboprophylaxis (83.4% of the entire cohort) and anticoagulant treatment (16.6%) were not associated with a decreased VTE risk. The incidence of VTE in patients hospitalized in non-ICU for COVID-19 was high despite the common use of thromboprophylaxis or anticoagulant treatment. A diagnosis of arterial hypertension and the need for oxygen therapy were associated with an increased VTE risk. Continuous D-dimer monitoring is required for the early detection of VTE.

The course of patients with hairy cell leukemia during the omicron surge of the Covid-19 pandemic

In this study, we aim to explore the outcomes of Covid-19 infection in patients with Hairy cell leukemia (HCL). The cohort is based on data obtained from electronic medical records. It includes 218 consecutive patients diagnosed with HCL between 16 June 1998, and 20 September 2022, out of which the coronavirus has infected 85 patients during the Omicron surge. Out of 85 patients with HCL who were infected by Covid-19; 7 patients (8.2%) have been hospitalized, and the mortality rate was 2.3% (two patients). Thirteen of the 85 patients had been infected by Covid-19 in previous waves, including 9/13 after vaccination, and none of them developed a severe disease. Humoral immune response after three doses of the BNT162b2 mRNA vaccination regimen was evaluated in 40 patients and was attained in 67.5%. Based on multivariate analysis: unfavorable outcome was significantly more common in patients with HCL above 65 years old, who had at least one cytopenia, and with comorbidity of cardiovascular disease or asplenia. Our results indicates that the course of COVID-19 in patients with HCL during the Omicron wave has been improved relatively favorable.

Cellular immune response to SARS-CoV-2 in patients with primary antibody deficiencies

Introduction

Primary antibody deficiencies (PAD) are inborn defects of the immune system that result in increased susceptibility to infections. Despite the reduced response to vaccination, PAD patients still benefit from it by reducing the risk of severe infections and complications. SARS-CoV-2 vaccines are recommended in PAD patients, but their immune effects are poorly studied. Here, we analyze virus-specific T-cell responses in PAD patients after booster vaccination against SARS-CoV-2.

Patients and methods

The study included 57 adult PAD patients on long-term immunoglobulin replacement therapy (IgRT) diagnosed with X-linked agammaglobulinemia (XLA; n = 4), common variable immunodeficiency (CVID; n = 33), isotype defects or IgG subclass deficiency (n = 6), and unclassified IgG deficiency (n = 14). Of those, 49 patients (86%) received vaccination against SARS-CoV-2 using mRNA vaccine (Pfizer-BioNTech). T-cell responses were assessed at a median of 21 (13 - 30) weeks after the booster dose (mainly the third dose) using commercially available interferon-gamma release assay (IGRA) with recombinant SARS-CoV-2 spike S1 protein.

Results

Vaccinated PAD patients showed an increased (3.8-fold, p = 0.004) release of IFN-γ upon S1 stimulation. In this group, we also documented higher serum levels of anti-SARS-CoV-2 IgG (4.1-fold, p = 0.01), although they were not associated with IGRA results. Further subgroup analysis revealed very similar IGRA responses in CVID and unclassified IgG deficiencies that were 2.4-fold increased compared to XLA and 5.4-fold increased compared to patients with isotype defects or IgG subclass deficiencies (e.g., vs. CVID: p = 0.016). As expected, CVID and XLA patients showed decreased serum titers of anti-SARS-CoV-2 antibodies compared to other studied groups (e.g., CVID vs. unclassified IgG deficiency: 4.4-fold, p = 0.006). The results did not depend directly on IgRT mode or dose, number of vaccine doses and time from the last booster dose, and clinical manifestations of PAD. Interestingly, anti-SARS-CoV-2 titers were positively correlated with serum immunoglobulin levels before IgRT (e.g., for IgA: r = 0.45, p<0.001; for IgG: r = 0.34, p = 0.009) and the percentage of peripheral blood NK cells (r = 0.48, p<0.001).

Conclusions

Our results documented satisfactory in vitro cellular immune response in PAD patients after booster SARS-CoV-2 vaccination. Therefore, even patients with agammaglobulinemia should benefit from vaccination due to the apparent induction of cell-mediated immunity, which, together with IgRT, grants comprehensive protection against the pathogen.

Key Considerations during the Transition from the Acute Phase of the COVID-19 Pandemic: A Narrative Review

The COVID-19 pandemic has been met with an unprecedented response from the scientific community, leading to the development, investigation, and authorization of vaccines and antivirals, ultimately reducing the impact of SARS-CoV-2 on global public health. However, SARS-CoV-2 is far from being eradicated, continues to evolve, and causes substantial health and economic burdens. In this narrative review, we posit essential points on SARS-CoV-2 and its responsible management during the transition from the acute phase of the COVID-19 pandemic. As discussed, despite Omicron (sub)variant(s) causing clinically milder infections, SARS-CoV-2 is far from being a negligible pathogen. It requires continued genomic surveillance, particularly if one considers that its future (sub)lineages do not necessarily have to be milder. Antivirals and vaccines remain the essential elements in COVID-19 management. However, the former could benefit from further development and improvements in dosing, while the seasonal administration of the latter requires simplification to increase interest and tackle vaccine hesitancy. It is also essential to ensure the accessibility of COVID-19 pharmaceuticals and vaccines in low-income countries and improve the understanding of their use in the context of the long-term goals of SARS-CoV-2 management. Regardless of location, the primary role of COVID-19 awareness and education must be played by healthcare workers, who directly communicate with patients and serve as role models for healthy behaviors.

Change in the Clinical Picture of Hospitalized Patients with COVID-19 between the Early and Late Period of Dominance of the Omicron SARS-CoV-2 Variant

This study aimed to compare the clinical picture of COVID-19 in the initial and later period of Omicron dominance and to identify populations still at risk. A retrospective comparison of the clinical data of 965 patients hospitalized during the early period of Omicron's dominance (EO, January-June 2022) with 897 patients from a later period (LO, July 2022-April 2023) from the SARSTer database was performed. Patients hospitalized during LO, compared to EO, were older, had a better clinical condition on admission, had a lower need for oxygen and mechanical ventilation, had less frequent lung involvement in imaging, and showed much faster clinical improvement. Moreover, the overall mortality during EO was 14%, higher than that in LO-9%. Despite the milder course of the disease, mortality exceeding 15% was similar in both groups among patients with lung involvement. The accumulation of risk factors such as an age of 60+, comorbidities, lung involvement, and oxygen saturation <90% resulted in a constant need for oxygen in 98% of patients, an 8% risk of mechanical ventilation, and a 30% mortality rate in the LO period. Multiple logistic regression revealed lower odds of death during the LO phase. Despite the milder course of infections caused by the currently dominant subvariants, COVID-19 prophylaxis is necessary in people over 60 years of age, especially those with comorbidities, and in the case of pneumonia and respiratory failure.

Clinical features of COVID-19 in Italian outpatient children and adolescents during Parental, Delta, and Omicron waves: a prospective, observational, cohort study

Introduction

COVID-19 features changed with the Omicron variant of SARS-CoV-2 in adults. This study aims to describe COVID-19 symptoms in children and adolescents during the Parental, Delta, and Omicron eras.

Methods

A single-centre, prospective observational study was conducted on individuals aged 0-20 years attending the University Hospital of Padua (Italy) from April 2020 to December 2022. COVID-19 cases were defined by positive SARS-CoV-2 molecular detection and/or serology; patient/family symptoms and virological positivity were considered to determine the infection onset. Variables were summarized and compared using appropriate tests of descriptive statistics.

Results

A total of 509 cases [46% female, median age eight years (IQR: 4-12)] were studied. Three-hundred-eighty-seven (76%), 52 (10%), and 70 (14%) subjects experienced COVID-19 during the Parental, Delta, and Omicron waves, respectively. All subjects developed an asymptomatic/mild COVID-19. Overall, the most frequent symptoms were fever (47%) and rhinitis (21%), which showed a significant increasing incidence from the Parental to Omicron waves (p < 0.001). Conversely, diarrhea was most common during the pre-Omicron eras (p = 0.03). Stratifying symptoms according to the age group, fever, rhinitis, and skin rashes were observed more frequently among infants/toddlers; conversely, fatigue was more common in children older than five years. The duration of symptoms was similar across different SARS-CoV-2 variants of concern (VOCs); conversely, the number of symptoms varied according to the age group (p < 0.0001).

Discussion

This study showed differences in COVID-19 clinical presentation among infants, children, and adolescents and confirmed Omicron infection is more likely to be associated with upper respiratory symptoms. However, further population-based studies are needed to support these findings. In addition, active surveillance will play a crucial role in assessing the disease severity of future VOCs.

Short-term exposure to ambient air pollution and COVID-19 severity during SARS-CoV-2 Delta and Omicron waves: A multicenter study

Air pollution may affect the clinical course of respiratory diseases, including COVID-19. This study aimed to evaluate the relationship between exposure of adult patients to mean 24 h levels of particulate matter sized <10 μm (PM₁₀ ) and <2.5 μm (PM_2.5 ) and benzo(a)pyrene (B(a)P) during a week before their hospitalization due to SARS-CoV-2 infection and symptomatology, hyperinflammation, coagulopathy, the clinical course of disease, and outcome. The analyses were conducted during two pandemic waves: (i) dominated by highly pathogenic Delta variant (n = 1440) and (ii) clinically less-severe Omicron (n = 785), while the analyzed associations were adjusted for patient's age, BMI, gender, and comorbidities. The exposure to mean 24 h B(a)P exceeding the limits was associated with increased odds of fever and fatigue as early COVID-19 symptoms, hyperinflammation due to serum C-reactive protein >200 mg/L and interleukin-6 >100 pg/mL, coagulopathy due to  d-dimer >2 mg/L and fatal outcome. Elevated PM₁₀ and PM_{2. 5} levels were associated with higher odds of respiratory symptoms, procalcitonin >0.25 ng/mL and interleukin >100 pg/mL, lower oxygen saturation, need for oxygen support, and death. The significant relationships between exposure to air pollutants and the course and outcomes of COVID-19 were observed during both pandemic waves. Short-term exposure to elevated PM and B(a)P levels can be associated with a worse clinical course of COVID-19 in patients requiring hospitalization and, ultimately, contribute to the health burden caused by SARS-CoV-2 variants of higher and lower clinical significance.

Unpacking the Complexity of COVID-19 Fatalities: Adverse Events as Contributing Factors-A Single-Center, Retrospective Analysis of the First Two Years of the Pandemic

In a retrospective analysis of 477 fatal COVID-19 cases hospitalised at a single medical centre during the period from 6 March 2020 to 30 June 2022, several factors defining those patients at admission were assessed, as well as the course of the hospitalisation and factors contributing to death. There was a predominance of men (59.3% (283)) burdened by comorbidities, with increased inflammation at admission. Patients aged ≥ 81 years were significantly more likely to be admitted to and die in infectious diseases units (IDU) due to respiratory failure, their hospital stays were shorter, and they were most likely not to receive specialist treatment. The most common COVID-19 complications included acute kidney injury in 31.2% (149) patients and thromboembolic complications in 23.5% (112). The course of hospitalisation was complicated by healthcare-associated infections (HAI) in 33.3% (159) of cases, more often in those treated with baricitinib (p < 0.001). The initial use of an antibiotic, although common (94.8% (452)), was unwarranted in almost half of the cases (47.6% (215)). Complications of hospitalisation (46.1% (220)) and adverse events involving staff (49.7% (237)) were found in almost half of the patients. In 88.7% (423) of the cases, death was due to respiratory failure in the course of SARS-CoV-2 infection. Adverse events during hospitalisation should be considered as an additional factor that, in addition to the infection itself, may have influenced the death of patients.

The COVID-19 pandemic in China: from dynamic zero-COVID to current policy

On 8 January 2023, after 3 years of pandemic control, China changed its management of COVID-19, applying measures against class B infectious diseases instead of Class A infectious diseases. This signaled the end of the dynamic zero-COVID policy and the reopening of the country. With a population of 1.41 billion, China's reopening policy during the COVID-19 pandemic has been characterized by a scientific, gradual, and cautious approach. Several factors contributed to the reopening policy, including an expansion of healthcare capacity, the widespread promotion and uptake of vaccination, and improved prevention and control mechanisms. According to the latest report from the Chinese Center for Disease Control and Prevention, the number of hospitalized COVID-19 patients in the country reached a peak of 1.625 million on January 5, 2023, and has since continued to decline. As of February 13, the number decreased to 26,000: a reduction of 98.4%. Thanks to the efforts of healthcare workers and society as a whole, the country managed to get through the peak of the epidemic in a stable manner.

Impact of the COVID-19 Pandemic on Attitudes toward Vaccination: Representative Study of Polish Society

The study explored the association between individuals' attitudes toward vaccination and their actual vaccination behavior. We also examined the impact of the coronavirus disease 2019 (COVID-19) pandemic and the ongoing vaccination debate on changing attitudes towards vaccination, specifically within different demographic groups. The survey was conducted among a representative sample of Poles (N = 805) using computer-assisted web interview (CAWI) technology. As demonstrated, those who identified themselves as strong vaccine supporters were statistically significantly more frequently to be vaccinated with COVID-19 booster doses, to follow a physician's recommendation on any vaccine without hesitation, and to be strengthened in their confidence in vaccines during the COVID-19 pandemic (p < 0.001 for all). However, over half of the responders declared themselves as moderate vaccine supporters/opponents, the groups whose further attitudes are likely to be affected by (mis)communication. Importantly, more than half of moderate vaccine supporters declared that their vaccine confidence was weakened during the COVID-19 pandemic, while 43% were not vaccinated against COVID-19. In addition, the study demonstrated that older and better-educated individuals were more likely to be COVID-19-vaccinated (p < 0.001 and p = 0.013, respectively). The results of this study imply that, in order to improve vaccine acceptance, it is essential to strengthen public health communication and avoid communication errors conducted during the COVID-19 pandemic.

Reduced Vessel Density and Enlarged Foveal Avascular Zone in the Macula as a Result of Systemic Hypoxia Caused by SARS-CoV-2 Infection

Infection with SARS-CoV-2 can lead to various long-term consequences, including those of an ophthalmic nature. This paper reviews the results of optical coherence tomography angiography (OCTA) performed among COVID-19 patients. The review included papers evaluating short- and long-term outcomes following the SARS-CoV-2 infection. Some differentiated the obtained retinal and choroidal vascularization parameters according to gender. Following COVID-19, patients reveal changes in retinal and choroidal vascular parameters based on OCTA, such as reduced vascular density and an increased foveal avascular zone, which can persist for several months. Routine ophthalmic follow-up with OCTA should be considered in patients after SARS-CoV-2 infection to assess the effects of inflammation and systemic hypoxia in COVID-19. Further research is needed to understand whether infection with particular viral variants/subvariants may vary in the risk of effects on retinal and choroidal vascularization and whether and to what extent these risks may also differ in relation to reinfected and vaccinated individuals.

Retrospective Analysis of the Effectiveness of Remdesivir in COVID-19 Treatment during Periods Dominated by Delta and Omicron SARS-CoV-2 Variants in Clinical Settings

Continuous evaluation of real-world treatment effectiveness of COVID-19 medicines is required due to the ongoing evolution of SARS-CoV-2 and the possible emergence of resistance. Therefore, this study aimed to analyze, in a retrospective manner, the outcomes in patients hospitalized with COVID-19 during the pandemic waves dominated by Delta and Omicron variants and treated with remdesivir (RDV) (n = 762) in comparison to a demographically and clinically matched group not treated with any antivirals (n = 1060). A logistic regression analysis revealed that RDV treatment was associated with a significantly lower risk of death during both Delta wave (OR = 0.42, 95%CI: 0.29-0.60; p < 0.0001) and Omicron-dominated period (OR = 0.56, 95%CI: 0.35-0.92; p = 0.02). Moreover, RDV-treated groups were characterized by a lower percentage of patients requiring mechanical ventilation, but the difference was not statistically significant. This study is the first real-world evidence that RDV remains effective during the dominance of more pathogenic SARS-CoV-2 variants and those that cause a milder course of the disease, and continues to be an essential element of COVID-19 therapy.

Association between the Seroprevalence of Antibodies against Seasonal Alphacoronaviruses and SARS-CoV-2 Humoral Immune Response, COVID-19 Severity, and Influenza Vaccination

The present study assesses the seroprevalence of antibodies against seasonal human alphacoronaviruses 229E and NL63 among adult patients infected with SARS-CoV-2, and its association with the humoral response to SARS-CoV-2 infection and its severity, and influenza vaccination. A serosurvey was conducted to quantify the presence of IgG antibodies against the nucleocapsid of 229E (anti-229E-N) and NL63 (anti-NL63-N), and anti-SARS-CoV-2 IgG antibodies (against nucleocapsid, receptor-binding domain, S2 domain, envelope, and papain-like protease) for 1313 Polish patients. The seroprevalence of anti-229E-N and anti-NL63 in the studied cohort was 3.3% and 2.4%. Seropositive individuals had a higher prevalence of anti-SARS-CoV-2 IgG antibodies, higher titers of the selected anti-SARS-CoV2 antibodies, and higher odds of an asymptomatic SARS-CoV-2 infection (OR = 2.5 for 229E and OR = 2.7 for NL63). Lastly, the individuals vaccinated against influenza in the 2019/2020 epidemic season had lower odds of seropositivity to 229E (OR = 0.38). The 229E and NL63 seroprevalence was below the expected pre-pandemic levels (up to 10%), likely due to social distancing, increased hygiene, and face masking. The study also suggests that exposure to seasonal alphacoronaviruses may improve humoral responses to SARS-CoV-2 while decreasing the clinical significance of its infection. It also adds to accumulating evidence of the favorable indirect effects of influenza vaccination. However, the findings of the present study are of a correlative nature and thereby do not necessarily imply causation.

mRNA vaccines: The future of prevention of viral infections?

Messenger RNA (mRNA) vaccines against COVID-19 are the first authorized biological preparations developed using this platform. During the pandemic, their administration has been proven to be a life-saving intervention. Here, we review the main advantages of using mRNA vaccines, identify further technological challenges to be met during the development of the mRNA platform, and provide an update on the clinical progress on leading mRNA vaccine candidates against different viruses that include influenza viruses, human immunodeficiency virus 1, respiratory syncytial virus, Nipah virus, Zika virus, human cytomegalovirus, and Epstein-Barr virus. The prospects and challenges of manufacturing mRNA vaccines in low-income countries are also discussed. The ongoing interest and research in mRNA technology are likely to overcome some existing challenges for this technology (e.g., related to storage conditions and immunogenicity of some components of lipid nanoparticles) and enhance the portfolio of vaccines against diseases for which classical formulations are already authorized. It may also open novel pathways of protection against infections and their consequences for which no safe and efficient immunization methods are currently available.