Machine learning of flow cytometry data reveals the delayed innate immune responses correlate with the severity of COVID-19.

Introduction: The COVID-19 pandemic has posed a major burden on healthcare and economic systems across the globe for over 3 years. Even though vaccines are available, the pathogenesis is still unclear. Multiple studies have indicated heterogeneity of immune responses to SARS-CoV-2, and potentially distinct patient immune types that might be related to disease features. However, those conclusions are mainly inferred by comparing the differences of pathological features between moderate and severe patients, some immunological features may be subjectively overlooked. Methods: In this study, the relevance scores(RS), reflecting which features play a more critical role in the decision-making process, between immunological features and the COVID-19 severity are objectively calculated through neural network, where the input features include the immune cell counts and the activation marker concentrations of particular cell, and these quantified characteristic data are robustly generated by processing flow cytometry data sets containing the peripheral blood information of COVID-19 patients through PhenoGraph algorithm. Results: Specifically, the RS between immune cell counts and COVID-19 severity with time indicated that the innate immune responses in severe patients are delayed at the early stage, and the continuous decrease of classical monocytes in peripherial blood is significantly associated with the severity of disease. The RS between activation marker concentrations and COVID-19 severity suggested that the down-regulation of IFN-γ in classical monocytes, Treg, CD8 T cells, and the not down-regulation of IL_17a in classical monocytes, Tregs are highly correlated with the occurrence of severe disease. Finally, a concise dynamic model of immune responses in COVID-19 patients was generalized. Discussion: These results suggest that the delayed innate immune responses in the early stage, and the abnormal expression of IL-17a and IFN-γ in classical monocytes, Tregs, and CD8 T cells are primarily responsible for the severity of COVID-19.

Proteomic Analysis of Human Milk Reveals Nutritional and Immune Benefits in the Colostrum from Mothers with COVID-19.

Despite the well-known benefits of breastfeeding and the World Health Organization's breastfeeding recommendations for COVID-19 infected mothers, whether these mothers should be encouraged to breastfeed is under debate due to concern about the risk of virus transmission and lack of evidence of breastmilk's protective effects against the virus. Here, we provide a molecular basis for the breastfeeding recommendation through mass spectrometry (MS)-based proteomics and glycosylation analysis of immune-related proteins in both colostrum and mature breastmilk collected from COVID-19 patients and healthy donors. The total protein amounts in the COVID-19 colostrum group were significantly higher than in the control group. While casein proteins in COVID-19 colostrum exhibited significantly lower abundances, immune-related proteins, especially whey proteins with antiviral properties against SARS-CoV-2, were upregulated. These proteins were detected with unique site-specific glycan structures and improved glycosylation diversity that are beneficial for recognizing epitopes and blocking viral entry. Such adaptive differences in milk from COVID-19 mothers tended to fade in mature milk from the same mothers one month postpartum. These results suggest that feeding infants colostrum from COVID-19 mothers confers both nutritional and immune benefits, and provide molecular-level insights that aid breastmilk feeding decisions in cases of active infection.

Proteomic Analysis of Human Milk Reveals Nutritional and Immune Benefits in the Colostrum from Mothers with COVID-19

Despite the well-known benefits of breastfeeding and the World Health Organization's breastfeeding recommendations for COVID-19 infected mothers, whether these mothers should be encouraged to breastfeed is under debate due to concern about the risk of virus transmission and lack of evidence of breastmilk's protective effects against the virus. Here, we provide a molecular basis for the breastfeeding recommendation through mass spectrometry (MS)-based proteomics and glycosylation analysis of immune-related proteins in both colostrum and mature breastmilk collected from COVID-19 patients and healthy donors. The total protein amounts in the COVID-19 colostrum group were significantly higher than in the control group. While casein proteins in COVID-19 colostrum exhibited significantly lower abundances, immune-related proteins, especially whey proteins with antiviral properties against SARS-CoV-2, were upregulated. These proteins were detected with unique site-specific glycan structures and improved glycosylation diversity that are beneficial for recognizing epitopes and blocking viral entry. Such adaptive differences in milk from COVID-19 mothers tended to fade in mature milk from the same mothers one month postpartum. These results suggest that feeding infants colostrum from COVID-19 mothers confers both nutritional and immune benefits, and provide molecular-level insights that aid breastmilk feeding decisions in cases of active infection.

Modification of Lipid-Based Nanoparticles: An Efficient Delivery System for Nucleic Acid-Based Immunotherapy.

Lipid-based nanoparticles (LBNPs) are biocompatible and biodegradable vesicles that are considered to be one of the most efficient drug delivery platforms. Due to the prominent advantages, such as long circulation time, slow drug release, reduced toxicity, high transfection efficiency, and endosomal escape capacity, such synthetic nanoparticles have been widely used for carrying genetic therapeutics, particularly nucleic acids that can be applied in the treatment for various diseases, including congenital diseases, cancers, virus infections, and chronic inflammations. Despite great merits and multiple successful applications, many extracellular and intracellular barriers remain and greatly impair delivery efficacy and therapeutic outcomes. As such, the current state of knowledge and pitfalls regarding the gene delivery and construction of LBNPs will be initially summarized. In order to develop a new generation of LBNPs for improved delivery profiles and therapeutic effects, the modification strategies of LBNPs will be reviewed. On the basis of these developed modifications, the performance of LBNPs as therapeutic nanoplatforms have been greatly improved and extensively applied in immunotherapies, including infectious diseases and cancers. However, the therapeutic applications of LBNPs systems are still limited due to the undesirable endosomal escape, potential aggregation, and the inefficient encapsulation of therapeutics. Herein, we will review and discuss recent advances and remaining challenges in the development of LBNPs for nucleic acid-based immunotherapy.

Association between health behaviours and the COVID-19 vaccination: risk compensation among healthcare workers in Taizhou, China.

This study is conducted to explore the association between health behaviors and the COVID-19 vaccination based on the risk compensation concept among health-care workers in Taizhou, China. We conducted a self-administered online survey to estimate the health behaviors among the staff in a tertiary hospital in Taizhou, China, from May 18 to 21 May 2021. A total of 592 out of 660 subjects (89.7%) responded to the questionnaire after receiving an e-poster on WeChat. Subjects who had been inoculated with the COVID-19 vaccine were asked to mention the differences in their health behaviors before and after the vaccination. The results showed that there were no statistical differences in health behaviors between vaccinated and unvaccinated groups, except in terms of the type of gloves they used (62.8% in the vaccinated group and 49.2% in the unvaccinated group, p = .048). Subjects who received earlier COVID-19 vaccinations exhibited better health behaviors (22.40% increased for duration of wearing masks (P = .007), 25.40% increased for times of washing hands (P = .01), and 20.90% increased for times of wearing gloves (P = .01)). Subjects also revealed better health behaviors (washing hands, wearing gloves, and wearing masks) after vaccination compared to that before. In conclusion, concept of risk compensation was not applied in our findings. The health behaviors did not reduce after the COVID-19 vaccination, which even may improve health behaviors among health-care workers in the hospital setting.

Recover the food-energy-water nexus from COVID-19 under Sustainable Development Goals acceleration actions.

The interwoven relationship between food, energy, and water (FEW) is described as the FEW nexus. The COVID-19 pandemic has interrupted the FEW nexus and impeded the progress of FEW-related Sustainable Development Goals (SDGs) (SDG 2: Zero Hunger; 6: Clean Water and Sanitation; 7: Affordable and Clean Energy). We aim to find solutions to recover the FEW nexus from COVID-19. First, we discussed the challenges faced by FEW amid COVID-19. Second, we observed responses of the FEW nexus under COVID-19's interference. Finally, we proposed the solutions that guide the FEW nexus in recovery from the pandemic by mining 164 FEW-related SDG Acceleration Actions. The key solutions include 1) building or upgrading FEW facilities and infrastructure, 2) improving nature's contribution to the FEW nexus, 3) developing digital technologies, 4) innovating the source and production of FEW, and 5) promoting community production and transforming the lifestyle. Our work highlights the importance of feasible and accelerated actions that recover the FEW nexus in the post-pandemic era.

Factors That Shape Women's Physical Activity: Development of the Reasons to Participate in Physical Activity Scale (RPPAS).

(1) Background: Obesity could deepen women's susceptibility to COVID-19 infections and deaths. While physical activity has the potential to improve women's physical and psychological resilience to the pandemic, there is a dearth of research on factors that motivate women's participation in physical activity. Thus, to bridge the research gap, this study aims to identify factors that motivate women's participation in physical activity. (2) Methods: An online survey on motivations for physical activity was developed and distributed to the participants. A total of 108 women offered complete answers (N = 108, 18-33 years old, Mage = 20.34 ± 2.42 years). Participants selected factors that promote their physical activity from a list of 34 factors from the Reasons to Participate in Physical Activity Scale (RPPAS) developed in this study. (3) Results: Exploratory factor analysis revealed that factors that motivate women's participation in physical activity are: enjoyment and gratification, consideration for other activities (i.e., exergaming), health benefits, networking opportunities, and appearance and performance. Multiple linear regression analyses indicate that only consideration for appearance and performance was significantly associated with participants' physical activity levels after controlling for compounding factors. (4) Conclusions: The findings of this study underscore the importance of appearance and performance in shaping women's participation in physical activity. Furthermore, the results also emphasize the need for a nuanced understanding of factors that influence women's physical activity levels. Future research could investigate how to leverage these motivators in tailored health interventions that aim to improve women's physical activity.

Using Fuzzy AHP-PROMETHEE for Market Risk Assessment of New-Build River Cruises on the Yangtze River

Cruise tourism on the Yangtze River Basin has developed rapidly in recent years. However, it is still facing such challenges as homogenization of itinerary and shore attraction arrangement, as well as aging cruise ships and simplification of service facilities, while it is also difficult to satisfy hierarchical and personalized tourist needs. To change such circumstances, new-build river cruise ships are inevitable. Complexity of market supply and demand environment, together with variability of tourist preferences, have increased market uncertainties of new-build cruise products. This study aims to assess market risks of new-build river cruise ships first by identifying risk factors, from the perspective of supply and demand under the actual conditions of the Yangtze River cruise market, then by evaluating potential impacts, caused by risk factors based on multi-criteria decision-making considerations. Fuzzy AHP-PROMETHEE was employed to prioritize the risk factors. The results reveal that among the most significant market risk factors are the following, in sequence: backwardness of support facilities;sudden security crisis;homogenization of cruise products;simplification of tourism route design;and inadequate management of the tourism market. Such findings will provide beneficial insights for strategic and sustainable development of river cruises on the Yangtze River.

The social and occupational consequences of the COVID-19 pandemic among patients with multiple sclerosis in three distinct populations: A web-based cross-sectional survey

Background The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes the disease COVID-19, has caused a pandemic that has rapidly affected the whole world and caused a significant threat to public health. The aim of this study was to investigate and analyze the social and occupational effects of the COVID-19 pandemic on patients with multiple sclerosis (MS) in three different countries: China, Spain, and Cuba. Methods A cross-sectional survey was designed to assess the social and occupational effects of the COVID-19 pandemic in MS patients in these three countries, using a 25-item anonymous online questionnaire, structured into three sections. Quantitative data are expressed as mean (standard deviation), and quantitative data as absolute frequency and percentage. Results A total of 361 participants responded to the questionnaire: 194 from China, 104 from Spain, and 63 from Cuba. We found no cases of COVID-19 among Chinese patients with MS, and few cases in Spain and Cuba. Respondents reported different levels of impact on relationships with friends, family, and colleagues, and patients in all three countries described increased use of digital or social media platforms. Spanish patients reported a significantly less negative impact than those in Cuba and China. Mental and cognitive effects were similar in all three countries, although China seemed to have a better situation. We also found that the time spent exercising decreased at specific points during the pandemic, but with few changes in dietary habits. Patients reported little or no change in their means of transport in all three countries. Most patients in all three countries reported little or no physical deterioration, especially in Chinese patients (82.47%), compared to the Spanish (70.20%) and Cuban respondents (73.02%). In general, patients from all three countries demonstrated confidence in overcoming the COVID-19 pandemic, although to a lesser extent among Spanish respondents. Conclusions During the pandemic, family support was more effective in China than in Cuba and Spain. Neither COVID-19 infections nor the number of MS relapses increased significantly during lockdown in any of the three countries. Regarding their economic situation, Spanish MS patients reported a significantly less severe negative impact than those in Cuba and China. Patients from all three countries used digital or social media platforms more frequently, probably to maintain personal relationships. Chinese and Cuban respondents were more confident of the control of the pandemic than the Spanish, who were more pessimistic.

Risk of First-Episode Schizophrenia in Aged Adults Increased During COVID-19 Outbreak.

We noticed an unusual increase of aged adults in first-episode schizophrenia in January and February 2020 since the outbreak of COVID-19. This retrospective study aims to statistically validate this observation and find potential risk factors, if applicable. The demographics of schizophrenia in outpatients (both first-episode and follow-up) from January to March 2020 (36,624 records) and similar periods of 2017-2019 (114,141 records) were analyzed and compared to minimize seasonal influence. Limited personal information (age, gender, approximate residence) was investigated to find risk factors. After considering seasonal factors such as the Spring festival, the age of the first-episode schizophrenia was significantly increased in January (46.60 ± 15.14) and February (51.53 ± 14.74) but went back to normal in March 2020 (38.89 ± 14.59), compared with similar periods from 2017 to 2019 (Jan., 40.77 ± 15.26; Feb., 39.69 ± 15.10; Mar., 42.04 ± 15.83). Meanwhile, a slight but not significant change was found in the distribution of gender and approximate residence (urban/suburb). Our data supported that risk of first-episode schizophrenia in aged adults increased during the COVID-19 outbreak, which is consistent with the fact that COVID-19 is more lethal to elders. Public healthcare should prepare in advance for potential risks in public mental health, especially for elders.

The Beneficial Role of Auricular Point Pressure in Insomnia and Anxiety in Isolated COVID-19 Patients.

BACKGROUND: Coronavirus disease 2019 (COVID-19) causes psychological distress and can have a negative impact on the general mental health and rehabilitation in affected patients under currently implemented isolation guidelines. Auricular point pressure (APP) as well-established technique in traditional Chinese medicine may help to relieve sleep disturbance and anxiety in COVID-19 patients. METHODS: During the early phase of the epidemic/pandemic, patients were enrolled in this study (02/2020 until 03/2020 n = 84). They were strictly isolated on specific wards at the Hubei Provincial Hospital of Integrated Chinese and Western Medicine in Hubei. The retrospective cohort study design included two groups. Group A patients were treated with an auricular point pressure (APP) in addition to standard intensive care medicine while Group B participants (No-APP) received routine nursing measures alone. Treatment outcome was measured using the St. Mary's Hospital Sleep Questionnaire (SMH) Score and the 7-Item Generalized Anxiety Disorder Scale (GAD-7). Both scores were measured in each patient at baseline and on the discharge day. RESULTS: The SMH score and sleep status changed in APP patients at the end of the treatment period when compared with No-APP patients (P < 0.01). APP-treated patients demonstrated lower GAD-7 scores than No-APP controls (P < 0.01). Further, no significant differences in safety or adverse events between the APP and No-APP groups were observed. CONCLUSION: The results from our snapshot study during the early phase of the SARS-CoV-2 epidemic/pandemic suggest that auricular point pressure could be a simple and effective tool to relieve insomnia and situational anxiety in hospitalized patients suffering from COVID-19 and kept under disconcerting conditions of isolation.

The People Still Make the (Remote Work-) Place: Lessons from a Pandemic

The Journal of Management editorial team challenged us to consider how the COVID-19 pandemic impacted and altered the employer?employee relationship. In this guest editorial, we take stock of the pandemic-related lessons learned for human resources research and practice. We highlight three insights that many organizations made as the result of pandemic-related changes and describe how these lessons are likely to alter the employee?employer landscape for the foreseeable future. The lessons are (a) understanding that organizational communication practices should be authentic, continuous, and two-way in nature;(b) accepting that the virtual workforce brings unique challenges that do not yet have solutions;and (c) recognizing that success for stakeholders beyond just investors will require continual attention and intention. We also highlight needs and opportunities for future research that will inform theory and practice and lead to the betterment of organizations and society.

Community structure of environmental microorganisms associated with COVID-19 affected patients.

To clarify the characteristics and distribution of hospital environmental microbiome associated with confirmed COVID-19 patients. Environmental samples with varying degrees of contamination which were associated with confirmed COVID-19 patients were collected, including 13 aerosol samples collected near eight patients in different wards, five swabs from one patient's skin and his personal belongings, and two swabs from the surface of positive pressure respiratory protective hood and the face shield from a physician who had close contact with one patient. Metagenomic next-generation sequencing (mNGS) was used to analyze the composition of the microbiome. One of the aerosol samples (near patient 4) was detected positive for COVID-19, and others were all negative. The environmental samples collected in different wards possessed protean compositions and community structures, the dominant genera including Pseudomonas, Corynebacterium, Neisseria, Staphylococcus, Acinetobacter, and Cutibacterium. Top 10 of genera accounted for more than 76.72%. Genera abundance and proportion of human microbes and pathogens radiated outward from the patient, while the percentage of environmental microbes increased. The abundance of the pathogenic microorganism of medical supplies is significantly higher than other surface samples. The microbial compositions of the aerosol collected samples nearby the patients were mostly similar to those from the surfaces of the patient's skin and personal belongings, but the abundance varied greatly. The positive rate of COVID-19 RNA detected from aerosol around patients in general wards was quite low. The ward environment was predominantly inhabited by species closely related to admitted patients. The spread of hospital microorganisms via aerosol was influenced by the patients' activity. Supplementary Information: The online version contains supplementary material available at 10.1007/s10453-021-09708-5.

Cancer patient management strategy in a Cancer Center of Zhejiang, China during the COVID-19 pandemic.

BACKGROUND: Due to the increased risk of viral infection and the severe shortage of medical resources during the pandemic of COVID-19, most hospitals in the epidemic areas significantly reduced non-emergency admissions and services, if not closed. As a result, it has been difficult to treat cancer patients on time, which adversely affects their prognosis. To address this problem, cancer centers must develop a strategic plan to manage both inpatients and outpatients during the pandemic, provide them with the necessary treatment, and at the same time prevent the spread of the virus among patients, visitors and medical staff. METHODS: Based upon the epidemic situation in Zhejiang Province, China, the number of running non-emergency medical wards in the Zhejiang Cancer Hospital was gradually increased in a controlled manner. All staff of the hospital received COVID-19 preventive training and was provided with three different levels of protection according to the risks of their services. Only patients without a known history of SARS-CoV-2 contact were eligible to schedule an appointment. Body temperature was measured on all patients upon their arrival at the hospital. Chest CT image, blood cell counting and travel/contact history were investigated in patients with fever. Respiratory tract samples, such as sputum and throat swabs, from all patients, including those clinically suspected of SARS-CoV-2 infection, were collected for nucleic acid detection of SARS-CoV-2 before treatment. RESULTS: A total of 3697 inpatients and 416 outpatients seeking cancer treatment were enrolled from February 1 to April 3, 2020, in compliance with the hospital's infection-control interventions. The clinicopathological parameters of the patients were summarized herein. 4237 samples from 4101 patients produced negative RNA testing results. Four clinically suspected patients all presented negative RNA test results and were excluded from the SARS-CoV-2 infection through follow-up retesting and monitoring. Seven patients with only N-gene positive results were retested, followed by CT scan and SARS-CoV-2 contact history investigation. All of them were finally diagnosed as non-infected patients. There was one outpatient who was confirmed positive by virus RNA test and then followed up. She might be an asymptomatic laboratory-confirmed case. During the study period, there was no SARS-CoV-2 infection among staff, patients and escorts of patients in the Zhejiang Cancer Hospital. CONCLUSION: This study suggested our infection-control interventions, including viral nucleic acid test, could be used as a reliable method to screen cancer patients in the area with moderate COVID-19 prevalence. Cancer may not be a high-risk factor of SARS-CoV-2 infection.

The effect of nationwide quarantine on anxiety levels during the COVID-19 outbreak in China.

BACKGROUND: In the recent outbreak of COVID-19, many countries have enacted various kinds of quarantine measures to slow down the explosive spread of COVID-19. Although these measures were proven to be successful in stopping the outbreak in China, the potential adverse effects of countrywide quarantine have not been thoroughly investigated. METHODS: In this study, we performed an online survey to evaluate the psychological effects of quarantine using the Zung Self-rating Anxiety Scale in February 2020 when the outbreak had nearly peaked in China. Along with the anxiety scores, limited personal information, such as age, gender, region, education, occupation, and specifically, the type and duration of quarantine, was collected for analysis. RESULTS: From a total of 992 valid questionnaires from 23 provinces in China, clinically significant anxiety symptoms were observed in 9.58% of respondents according to clinical diagnostic standards in China. The specific groups of people showing higher levels of anxiety were (a) adolescents (<18 years); (b) respondents with education lower than junior high school; (c) people with chronic diseases; and (d) frontline medical personnel. Other characteristics, such as gender, marital status, region, and acquaintance with suspected or confirmed cases of COVID-19, did not affect anxiety levels significantly. Respondents who experienced different forms of quarantine showed different anxiety levels. People undergoing centralized quarantine have higher levels of anxiety. Unexpectedly, longer durations of quarantine did not lead to a significant increase in anxiety level. CONCLUSIONS: Our results suggest a rather mild psychological influence caused by the countrywide quarantine during the COVID-19 outbreak in China and provide a reference for other countries and regions battling COVID-19.

Impact of COVID-19 on China's agricultural trade

Purpose The outbreak of the novel COVID-19 virus has spread throughout the world, causing unprecedented disruption to not only China's agricultural trade but also the world's agricultural trade at large. This paper attempts to provide a preliminary analysis of the impact of the COVID-19 pandemic on China's agricultural importing and exporting from both short- and long-term perspectives. Design/methodology/approach This study seeks to analyze how the outbreak of COVID-19 could potentially impact China's agricultural trade. With respect to exports, the authors have pinpointed major disruptive factors arising from the pandemic which have affected China's agricultural exports in both the short and long term;in doing so, we employ scenario analysis which simulates potential long-term effects. With regard to imports, possible impacts of the pandemic regarding the prospects of food availability in the world market are investigated. Using scenario analysis, the authors estimate the potential change in China's food market-especially meat import growth-in light of the implementation of the newly signed Sino-US Economic and Trade Agreement (SUETA). Findings The results show that China's agricultural exports have been negatively impacted in the short-term, mostly due to the disruption of the supply chain. In the long term, dampened external demand and potential imposition of non-tariff trade barriers (NTBs) will exert more profound and lasting negative effects on China's agricultural export trade. On the other hand, despite panic buying and embargoing policies from some exporting and importing countries, the world food availability and China's food import demand are still optimistic. The simulation results indicate that China's import of pork products, in light of COVID-19 and the implementation of SUETA, would most likely see a sizable climb in quantity, but a lesser climb in terms of value. Originality/value Agricultural trade in China has been a focal-point of attention in recent years, with new challenges slowing exports and increasing dependence on imports for food security. The outbreak of the COVID-19 pandemic adds significant uncertainty to agricultural trade, giving rise to serious concerns regarding its potential impact. By exploring the impact of the unprecedented pandemic on China's agricultural trade, this study should contribute to a better understanding of the still-evolving pandemic and shed light on pertinent policy implications.

A follow-up study of children infected with SARS-CoV-2 from western China.

BACKGROUND: To clarify the characteristic and the duration of positive nucleic acid in children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including asymptomatic children. METHODS: A total of 32 children confirmed with SARS-CoV-2 infection between January 24 and February 12, 2020 from four provinces in western China were enrolled in this study and followed up until discharge and quarantine 14 days later. RESULTS: Eleven children (34%) were asymptomatic, among whom six children had normal computed tomographic (CT) scan images. Age and gender were not associated with clinical symptoms or the results of CT scan in children infected with SARS-CoV-2. The concentrations of white blood cells and neutrophils were higher in children with asymptomatic infection than in children with clinical symptoms or CT abnormalities. Patients who presented with CT abnormalities had lower D-dimer or lower total bilirubin than those who had normal CT scan but clinical symptoms. All children recovered and no one died or was admitted to the pediatric intensive care unit (PICU). The mean duration of positive SARS-CoV-2 nucleic acid was 15.4 (SD =7.2) days and similar for both asymptomatic children and children with symptoms or CT abnormalities. We found a significant negative correlation between the lymphocyte count and the duration of positive nucleic acid test. CONCLUSIONS: Children with asymptomatic infection should be quarantined for the same duration as symptomatic patients infected with SARS-CoV-2. The clinical significance and mechanism behind the negative correlation between the number of lymphocytes and the duration of positive SARS-CoV-2 needs further study.

Initial chest CT findings in COVID-19: correlation with clinical features.

In December 2019, coronavirus disease 2019 (COVID-19), a new de novo infectious disease, was first identified in Wuhan, China and quickly spread across China and around the world. The etiology was a novel betacoronavirus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Lu et al., 2020). On Mar. 11, 2020, World Health Organization (WHO) characterized COVID-19 as a global pandemic. As of Mar. 22, 2020, over 292 000 confirmed COVID-19 cases have been reported globally. To date, COVID-19, with its high infectivity, has killed more people than severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) combined (Wu and McGoogan, 2020).