Immunological map in COVID-19

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by SARS-CoV-2, a newly discovered coronavirus that exhibits many similarities with the severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses (SARS-CoV and MERS-CoV, respectively). The definite pathogenesis and immunological influences of SARS-CoV-2 have not been fully elucidated. Therefore, we constructed a brief summary comparison of SARS-CoV-2, SARS-CoV, and MERS-CoV infections regarding their immunological changes. In addition, we further investigated the immunological differences between severe and nonsevere COVID-19 cases, and we searched for possible immunological predictors of the patient outcome by reviewing case series studies to date. Possible immunological predictors of a poor outcome are leukocytosis, neutrophilia, lymphopenia (both CD4 and CD8 T cells), an increased neutrophil-to-lymphocyte ratio (NLR), and increased levels of pro-inflammatory cytokines (IL-6 and TNF-α), Th1 cytokines (IL-2 and IFN-γ), regulatory T cell cytokines (IL-10) and Th17 cytokines (IL-17). A more precise immunological map needs to be established, which may assist in diagnosing this disease and facilitate immunological precision medicine treatment.     

Obesity and COVID-19: The Two Sides of the Coin

The World Health Organization declared COVID-19, the infectious disease caused by the coronavirus SARS-CoV-2, a pandemic on March 12, 2020. COVID-19 is causing massive health problems and economic suffering around the world. The European Association for the Study of Obesity (EASO) promptly recognised the impact that the outbreak could have on people with obesity. On one side, emerging data suggest that obesity represents a risk factor for a more serious and complicated course of COVID-19 in adults. On the other side, the health emergency caused by the outbreak diverts attention from the prevention and care of non-communicable chronic diseases to communicable diseases. This might be particularly true for obesity, a chronic and relapsing disease frequently neglected and linked to significant bias and stigmatization. The Obesity Management Task Force (OMTF) of EASO contributes in this paper to highlighting the key aspects of these two sides of the coin and suggests some specific actions.     

Optimal Social Distancing Policy for COVID-19 Control in Korea: A Model-Based Analysis

BackgroundSince March 2020, when coronavirus disease 2019 (COVID-19) was declared a pandemic, many countries have applied unprecedented restrictive measures to contain the spread of the virus. This study aimed to explore the optimal social distancing policy for COVID-19 control in South Korea to safely reopen the society.MethodsWe developed an age-specific, deterministic compartment epidemic model to examine the COVID-19 control decision-making process, including the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between 1 July 2021 and 30 December 2022. The model consists of the natural history of COVID-19, testing performance, vaccinations, and social distancing enforcement measures to detect and control SARS-CoV-2. We modelled potential intervention scenarios with three distinct components: 1) social distancing duration and level; 2) testing intensity; and 3) vaccination uptake rate. The primary and secondary outcomes were COVID-19 incidence and prevalence of severe patients requiring intensive care unit (ICU) care.ResultsFour (or more) months of social distancing (that can reduce 40–60% transmission) may mitigate epidemic resurgence and ICU demand in the future and keep the cases below the capacity limit if the testing intensity and vaccination rate remain constant or increase by 20% (with respect to the current level). In contrast, two months of strict social distancing enforcement may also successfully mitigate future epidemic surge and ICU demand as long as testing intensity and vaccination rates are increased by 20%.ConclusionIn South Korea, given the relatively high vaccination coverage and low incidence, four or more months of social distancing enforcement can effectively mitigate epidemic resurgence after lifting the social distancing measures. In addition, increasing the testing intensity and vaccination rate may help reduce necessary social distancing levels and duration to prevent a future epidemic resurgence and mitigate social and economic damage.     

Vaccines and autoimmunity during the COVID-19 pandemic

To control the pandemic, efficient vaccines must be applied to the population, including patients with autoimmune diseases. Therefore, one can expect that coronavirus disease 2019 (COVID-19) vaccines may influence the underlying autoimmune processes in these patients. Additionally, it is essential to understand whether COVID-19 vaccines would be effective, safe, and provide long-lasting immunological protection and memory. However, the currently available and approved COVID-19 vaccines turned out to be safe, effective, and reliable in patients with autoimmune inflammatory and rheumatic diseases. Furthermore, most patients said they felt safer after getting vaccinations for COVID-19 and reported enhanced overall quality of life and psychological wellbeing. In general, the COVID-19 vaccines have been highly tolerated by autoimmune patients. Such findings might comfort patients who are reluctant to use COVID-19 vaccines and assist doctors in guiding their patients into receiving vaccinations more easily and quickly.     

COVID-19 vaccines: Knowing the unknown

Vaccine development against SARS-CoV-2 has drawn attention around the globe due to the exploding pandemic. Although COVID-19 is caused by a new coronavirus, SARS-CoV-2, previous research on other coronavirus vaccines, such as FIPV, SARS, and MERS, has provided valuable information for the rapid development of COVID-19 vaccine. However, important knowledge gaps remain — some are specific to SARS-CoV-2, others are fundamental to immunology and vaccinology. Here, we discuss areas that need to be addressed for COVID-19 vaccine development, and what can be learned from examples of vaccine development in the past. Since the beginning of the outbreak, the research progress on COVID-19 has been remarkable. We are therefore optimistic about the rapid development of COVID-19 vaccine.     

Editorial commentary on special issue of COVID-19 pandemic

This special issue of The Journal of Biomedical Research presents rigorous empirical analysis related to COVID-19 research in responding to the current global COVID-19 pandemic. Selected articles from different disciplines not only offer broader perspectives on combating the outbreaks, but also disseminate the most updated findings on this new challenge for human being to the field.     

Case of COVID-19 presenting with gastrointestinal symptoms

Patients with coronavirus disease 2019 (COVID-19) predominantly present with the pulmonary symptoms such as fever, cough, and shortness of breath. We present a case of an 83 years old patient with COVID-19 who presented with only gastrointestinal symptoms without respiratory complaints. Our case raises the concern regarding our current lack of understanding of extrapulmonary manifestations of COVID-19. Given genetic homology between 2019 severe acute respiratory syndrome coronavirus (SARS-CoV) 2 and SARS-CoV, our case underscores the urgent need for further studies to understand the role of the gastrointestinal system in 2019 SARS-CoV-2 transmission and COVID-19 pathogenesis.     

National case fatality rates of the COVID-19 pandemic

ObjectivesThe case fatality rate (CFR) of coronavirus disease 2019 (COVID-19) varies significantly between countries. We aimed to describe the associations between health indicators and the national CFRs of COVID-19.MethodsWe identified for each country health indicators potentially associated with the national CFRs of COVID-19. We extracted data for 18 variables from international administrative data sources for 34 member countries of the Organization for Economic Cooperation and Development (OECD). We excluded the collinear variables and examined the 16 variables in multivariable analysis. A dynamic web-based model was developed to analyse and display the associations for the CFRs of COVID-19. We followed the Guideline for Accurate and Transparent Health Estimates Reporting (GATHER).ResultsIn multivariable analysis, the variables significantly associated with the increased CFRs were percentage of obesity in ages >18 years (β = 3.26; 95%CI = 1.20, 5.33; p 0.003), tuberculosis incidence (β = 3.15; 95%CI = 1.09, 5.22; p 0.004), duration (days) since first death due to COVID-19 (β = 2.89; 95%CI = 0.83, 4.96; p 0.008), and median age (β = 2.83; 95%CI = 0.76, 4.89; p 0.009). The COVID-19 test rate (β = –3.54; 95%CI = –5.60, –1.47; p 0.002), hospital bed density (β = –2.47; 95%CI = –4.54, –0.41; p 0.021), and rural population ratio (β = –2.19; 95%CI = –4.25, –0.13; p 0.039) decreased the CFR.ConclusionsThe pandemic hits population-dense cities. Available hospital beds should be increased. Test capacity should be increased to enable more effective diagnostic tests. Older patients and patients with obesity and their caregivers should be warned about a potentially increased risk.     

Pathologic features of COVID-19: A concise review

The novel coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), first appeared in December 2019, in Wuhan, China and evolved into a pandemic. As Angiotensin-Converting Enzyme 2 (ACE2) is one of the potential target receptors for SARS-CoV-2 in human body, which is expressed in different tissues, multiple organs might become affected. In the initial phase of the current pandemic, a handful of post-mortem case-series revealed COVID-19-related pathological changes in various organs. Although pathological examination is not a feasible method of diagnosis, it can elucidate pathological changes, pathogenesis of the disease, and the cause of death in COVID-19 cases. Herein, we thoroughly reviewed multiple organs including lung, gastrointestinal tract, liver, kidney, skin, heart, blood, spleen, lymph nodes, brain, blood vessels, and placenta in terms of COVID-19-related pathological alterations. Also, these findings were compared with SARS and MERS infection, wherever applicable. We found a diverse range of pathological changes, some of which resemble those found in SARS and MERS.     

Multidisciplinary consensus on sputum induction biosafety during the COVID-19 pandemic

Sputum induction (SI) is the gold standard approach to the non-invasive study of airway inflammation. The differential count of inflammatory cells for SI allows patients with asthma to be classified according to inflammatory phenotypes and predicted therapeutic responses. Since SI involves the generation of aerosols, there is a need to establish a protocol to ensure biosafety in clinical practice during the current COVID-19 pandemic. The multidisciplinary consensus on SI described in this article was developed by 22 experts in SI from different Spanish hospitals who drew on available scientific evidence in achieving consensuated opinions, compiled by means of an electronic survey. We hope that these unified criteria and recommendations will guide health professionals in implementing SI sampling and processing procedures as safely as possible during the COVID-19 pandemic.     

Quercetin for the treatment of COVID-19 patients: A systematic review and meta-analysis

Currently approved therapies for COVID-19 are mostly limited by their low availability, high costs or the requirement of parenteral administration by trained medical personnel in an in-hospital setting. Quercetin is a cheap and easily accessible therapeutic option for COVID-19 patients. However, it has not been evaluated in a systematic review until now. We aimed to conduct a meta-analysis to assess the effect of quercetin on clinical outcomes in COVID-19 patients. Various databases including PubMed, the Cochrane Library and Embase were searched from inception until 5 October 2022 and results from six randomized controlled trials (RCTs) were pooled using a random-effects model. All analyses were conducted using RevMan 5.4 with odds ratio (OR) as the effect measure. Quercetin decreased the risk of intensive care unit admission (OR = 0.31; 95% confidence interval (CI) 0.10–0.99) and the incidence of hospitalisation (OR = 0.25; 95% CI 0.10–0.62) but did not decrease the risk of all-cause mortality and the rate of no recovery. Quercetin may be of benefit in COVID-19 patients, especially if administered in its phytosome formulation which greatly enhances its bioavailability but large-scale RCTs are needed to confirm these findings.     

COVID-19 associated with pulmonary aspergillosis: A literature review

Bacterial or virus co-infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported in many studies, however, the knowledge on Aspergillus co-infection among patients with coronavirus disease 2019 (COVID-19) was limited. This literature review aims to explore and describe the updated information about COVID-19 associated with pulmonary aspergillosis. We found that Aspergillus spp. can cause co-infections in patients with COVID-19, especially in severe/critical illness. The incidence of IPA in COVID-19 ranged from 19.6% to 33.3%. Acute respiratory distress syndrome requiring mechanical ventilation was the common complications, and the overall mortality was high, which could be up to 64.7% (n = 22) in the pooled analysis of 34 reported cases. The conventional risk factors of invasive aspergillosis were not common among these specific populations. Fungus culture and galactomannan test, especially from respiratory specimens could help early diagnosis. Aspergillus fumigatus was the most common species causing co-infection in COVID-19 patients, followed by Aspergillus flavus. Although voriconazole is the recommended anti-Aspergillus agent and also the most commonly used antifungal agent, aspergillosis caused by azole-resistant Aspergillus is also possible. Additionally, voriconazole should be used carefully in the concern of complicated drug–drug interaction and enhancing cardiovascular toxicity on anti-SARS-CoV-2 agents. Finally, this review suggests that clinicians should keep alerting the possible occurrence of pulmonary aspergillosis in severe/critical COVID-19 patients, and aggressively microbiologic study in addition to SARS-CoV-2 via respiratory specimens should be indicated.     

Caring for older adults during the COVID-19 pandemic

BackgroundElderly patients represent a high-risk group with increased risk of death from COVID-19. Despite the number of published studies, several unmet needs in care for older adults exist.ObjectivesTo discuss unmet needs of COVID-19 in this special population.SourcesA literature review for studies on COVID-19 in elderly patients published between December 2019 and November 2021 was performed. Clinical questions were formulated to guide the literature search. The search was conducted in the MEDLINE database, combining specific search terms. Two reviewers independently conducted the search and selected the studies according to the prespecified clinical questions.ContentElderly patients with COVID-19 have peculiar characteristics. They may have atypical clinical presentation, with no fever and with delirium or neurological manifestations as the most common signs, with potential delayed diagnosis and increased risk of death. The reported fatality rates among elderly patients with COVID-19 are extremely high. Several factors, including comorbidities, atypical presentation, and exclusion from intensive care unit care, contribute to this excess of mortality. Age alone is frequently used as a key factor to exclude the elderly from intensive care, but there is evidence that frailty rather than age better predicts the risk of poor outcome in this category. Durability of vaccine efficacy in the elderly remains debated, and the need for a third booster dose is becoming increasingly evident. Finally, efforts to care for elderly patients who have survived after acute COVID-19 should be implemented, considering the high rates of long COVID sequelae and the risk of longitudinal functional and cognitive decline.ImplicationsWe highlight peculiar aspects of COVID-19 in elderly patients and factors contributing to high risk of poor outcome in this category. We also illuminated gaps in current evidence, suggesting future research directions and underlining the need for further studies on the optimal management of elderly patients with COVID-19.     

Impact of the COVID-19 pandemic on pathological autopsy practices in Japan

During the coronavirus disease 2019 (COVID-19) pandemic, autopsies have provided valuable insights into the pathogenesis of COVID-19. The precise effect of this pandemic on autopsy procedures in Japan, especially in instances unrelated to COVID-19, has not yet been established. Therefore, we conducted a questionnaire survey from December 2020 to January 2021 regarding the status of pathological autopsy practices in Japan during the first year of the COVID-19 pandemic. The questionnaire was sent to 678 medical facilities with pathologists, of which 227 responded. In cases where a confirmed diagnosis of COVID-19 was not made at the time of autopsy, many facilities counted them as suspected COVID-19 cases if pneumonia was suspected clinically. At around half of the sites, autopsies were prohibited for suspected COVID-19 cases. In addition, the number of autopsies of non-COVID-19 cases during the pandemic period was also investigated, and a significant decrease was observed compared with the incidence in the pre-pandemic period. The COVID-19 pandemic has affected not only the autopsies of COVID-19 cases but also the entire practice of pathological autopsies. It is necessary to establish a system that supports the implementation of pathological autopsy practices during the pandemic of an emerging infectious disease.     

Vaccines and allergic reactions: The past,the current COVID-19 pandemic,and future perspectives

Vaccines are essential public health tools with a favorable safety profile and prophylactic effectiveness that have historically played significant roles in reducing infectious disease burden in populations, when the majority of individuals are vaccinated. The COVID-19 vaccines are expected to have similar positive impacts on health across the globe. While serious allergic reactions to vaccines are rare, their underlying mechanisms and implications for clinical management should be considered to provide individuals with the safest care possible. In this review, we provide an overview of different types of allergic adverse reactions that can potentially occur after vaccination and individual vaccine components capable of causing the allergic adverse reactions. We present the incidence of allergic adverse reactions during clinical studies and through post-authorization and post-marketing surveillance and provide plausible causes of these reactions based on potential allergenic components present in several common vaccines. Additionally, we review implications for individual diagnosis and management and vaccine manufacturing overall. Finally, we suggest areas for future research.