Remote learning and mental health during the societal lockdown: a study of primary school students and parents in times of COVID-19.

BACKGROUND: The COVID-19 pandemic has brought challenges to families around the world. The prolonged school closures in Hong Kong have forced young students to stay at home and adapt to remote learning for over a year, putting their mental health conditions at risk. Focusing on primary school students and their parents, the main objective of our research is to investigate the socioemotional factors and their associations with mental health conditions. METHODS: A total of 700 Hong Kong primary schoolers (mean age = 8.2) reported their emotional experiences, loneliness, and academic self-concept via a user-friendly online survey; 537 parents reported depression and anxiety, perceived child depression and anxiety, and social support. Responses from students and parents were paired to account for the family context. Structural Equation Modeling was used for correlations and regressions. RESULTS: The results of students' responses showed that positive emotional experiences were negatively associated with loneliness and positively related to academic self-concept among students. Furthermore, the paired sample results showed that, during the one-year societal lockdown and remote learning period, the socioemotional factors were associated with mental health conditions among primary school students and their parents. Among our family sample in Hong Kong, evidence supports the unique negative association between students-reported positive emotional experiences and parents-reported child depression and anxiety, as well as between social support and parents' depression and anxiety. CONCLUSIONS: These findings highlighted the associations between socioemotional factors and mental health among young primary schoolers during the societal lockdown. We thus call for more attention to the societal lockdown and remote learning context, especially since the social distancing practice could be "the new normal" for our society to handle the future pandemic crisis.

Removing Negative Impacts from Inevitable Nonreproducible and Nonspecific Antibody-Probe Interactions in Viral Serology.

Serological assays are indispensable tools in public health. Presently deployed serological assays, however, largely overlook research progress made in the last two decades that jeopardizes the conceptual foundation of these assays, i.e., antibody (Ab) specificity. Challenges to traditional understanding of Ab specificity include Ab polyspecificity and most recently nonreproducible Ab-probe interactions (NRIs). Here, using SARS-CoV-2 and four common livestock viruses as a test bed, we developed a new serological platform that integrates recent understanding about Ab specificity. We first demonstrate that the response rate (RR) from a large-sized serum pool (∼100) is not affected by NRIs or by nonspecific Ab-probe interactions (NSIs), so RR can be incorporated into the diagnostic probe selection process. We subsequently used multiple probes (configured as a "protein peptide hybrid microarray", PPHM) to generate a digital microarray index (DMI) and finally demonstrated that DMI-based analysis yields an extremely robust probabilistic trend that enables accurate diagnosis of viral infection that overcomes multiple negative impacts exerted by NSI/NRI. Thus, our study with SARS-CoV-2 confirms that the PPHM-RR-DMI platform enables very rapid development of serological assays that outperform traditional assays (for both sensitivity and specificity) and supports that the platform is extendable to other viruses.

A randomized controlled trial of heterologous ChAdOx1 nCoV-19 and recombinant subunit vaccine MVC-COV1901 against COVID-19.

Heterologous prime-boost COVID-19 vaccine strategy may facilitate mass COVID-19 immunization. We reported early immunogenicity and safety outcomes of heterologous immunization with a viral vector vaccine (ChAdOx1) and a spike-2P subunit vaccine (MVC-COV1901) in a participant-blinded, randomized, non-inferiority trial (NCT05054621). A total of 100 healthy adults aged 20-70 years having the first dose of ChAdOx1 were 1:1 randomly assigned to receive a booster dose either with ChAdOx1 (n = 50) or MVC-COV1901 (n = 50) at an interval of 4-6 or 8-10 weeks. At day 28 post-boosting, the neutralizing antibody geometric mean titer against wild-type SARS-CoV-2 in MVC-COV1901 recipients (236 IU/mL) was superior to that in ChAdOx1 recipients (115 IU/mL), with a GMT ratio of 2.1 (95% CI, 1.4 to 2.9). Superiority in the neutralizing antibody titer against Delta variant was also found for heterologous MVC-COV1901 immunization with a GMT ratio of 2.6 (95% CI, 1.8 to 3.8). Both spike-specific antibody-secreting B and T cell responses were substantially enhanced by the heterologous schedule. Heterologous boosting was particularly prominent at a short prime-boost interval. No serious adverse events occurred across all groups. The findings support the use of heterologous prime-boost with ChAdOx1 and protein-based subunit vaccines.

Improving transitional care through online communication skills training.

BACKGROUND: As the aging population is increasing significantly, the communication skills training (CST) on transitional care (TC) is insufficient. AIMS: This study aimed to test the effectiveness of an intervention (the online TC CST [OTCCST] and TC) through the perspectives of healthcare providers (HCPs), older patients, and family members. METHODS: A total of 38 HCPs caring for older patients were randomized to the experimental (n = 18) or control groups (n = 20), and 84 pairs of patients and family members were enrolled (experimental: n = 42 vs. control: n = 42). The primary outcome was HCP communication confidence; while secondary outcomes included patient quality of life (QoL), activities of daily living (ADL), rehospitalization counts, and family caregiving burden. Data were collected from HCPs using a scale measuring confidence in communicating with patients. Patient outcomes were assessed using the McGill QoL Questionnaire-Revised and Barthel Index. Family members were assessed with the Caregiver Burden Inventory. Rehospitalization counts were tracked for 3 months post-discharge. Data were analyzed using multiple regression analysis. RESULTS: Experimental group HCPs showed a significant improvement in communication confidence over the control group (p = 0.0006). Furthermore, experimental group patients had significantly fewer rehospitalization counts within 3-month post-discharge (p < 0.05). However, no significant group differences were found in patient QoL and ADL nor in family caregiver burden. CONCLUSION: The OTCCST can effectively improve HCP communication confidence, and the combination of OTCCST and TC can reduce rehospitalization counts for older patients. The OTCCST allows HCPs to learn asynchronously at their convenience, ideal for continuing education, especially during the COVID-19 pandemic.

Highly Sensitive Detection Method for HV69-70del in SARS-CoV-2 Alpha and Omicron Variants Based on CRISPR/Cas13a.

As SARS-CoV-2 variants continue to evolve, identifying variants with adaptive diagnostic tool is critical to containing the ongoing COVID-19 pandemic. Herein, we establish a highly sensitive and portable on-site detection method for the HV69-70del which exist in SARS-CoV-2 Alpha and Omicron variants using a PCR-based CRISPR/Cas13a detection system (PCR-CRISPR). The specific crRNA (CRISPR RNA) targeting the HV69-70del is screened using the fluorescence-based CRISPR assay, and the sensitivity and specificity of this method are evaluated using diluted nucleic acids of SARS-CoV-2 variants and other pathogens. The results show that the PCR-CRISPR detection method can detect 1 copies/µL SARS-CoV-2 HV69-70del mutant RNA and identify 0.1% of mutant RNA in mixed samples, which is more sensitive than the RT-qPCR based commercial SARS-CoV-2 variants detection kits and sanger sequencing. And it has no cross reactivity with ten other pathogens nucleic acids. Additionally, by combined with our previously developed ERASE (Easy-Readout and Sensitive Enhanced) lateral flow strip suitable for CRISPR detection, we provide a novel diagnosis tool to identify SARS-CoV-2 variants in primary and resource-limited medical institutions without professional and expensive fluorescent detector.

Severe Acute Respiratory Syndrome Coronavirus 2 Epitope Mapping for Antibodies.

Epitope mapping of the interactions between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Abs is challenging because of complexity in protein three-dimensional structures. Protein structure fingerprint technology was applied for epitope mapping of 44 SARS-CoV-2 Abs with three-dimensional structure complexes. The results defined how the epitopes were distributed on SARS-CoV-2 and how the patterns of six CDRs from Abs participated in neutralization. Also, the residue-residue recognition revealed that certain residues had higher frequencies on the interfaces between SARS-CoV-2 and Abs, and the activity correlated with the physicochemical properties of the residues at the interface. Thus, epitope mapping provides significant lead information for development of epitope-based designs for Abs, vaccines, and diagnostic reagents. This is a bioinformatics project of structural data analysis; no animals or cells were used.

Immunoglobin G Sero-Dynamics Aided Host Specific Linear Epitope Identification and Differentiation of Infected from Vaccinated Hosts.

Differentiation of infected from vaccinated hosts (DIVH) is a critical step in virus eradication programs. DIVH-compatible vaccines, however, take years to develop, and are therefore unavailable for fighting the sudden outbreaks that typically drive pandemics. Here, we establish a protocol for the swift and efficient development of DIVH assays, and show that this approach is compatible with any type of vaccines. Using porcine circovirus 2 (PCV2) as the experimental model, the first step is to use Immunoglobin G (IgG) sero-dynamics (IsD) curves to aid epitope discovery (IsDAED): PCV2 Cap peptides were categorized into three types: null interaction, nonspecific interaction (NSI), and specific interaction (SI). We subsequently compared IsDAED approach and traditional approach, and demonstrated identifying SI peptides and excluding NSI peptides supports efficient diagnostic kit development, specifically using a protein-peptide hybrid microarray (PPHM). IsDAED directed the design of a DIVH protocol for three types of PCV2 vaccines (while using a single PPHM). Finally, the DIVH protocol successfully differentiated infected pigs from vaccinated pigs at five farms. This IsDAED approach is almost certainly extendable to other viruses and host species. IMPORTANCE Sudden outbreaks of pandemics caused by virus, such as SARS-CoV-2, has been determined as a public health emergency of international concern. However, the development of a DIVH-compatible vaccine is time-consuming and full of uncertainty, which is unsuitable for an emergent situation like the ongoing COVID-19 pandemic. Along with the development and public health implementation of new vaccines to prevent human diseases, e.g., human papillomavirus vaccines for cervical cancer; enterovirus 71 vaccines for hand, foot, and mouth disease; and most recently SARS-CoV-2, there is an increasing demand for DIVH. Here, we use the IsDAED approach to confirm SI peptides and to exclude NSI peptides, finally to direct the design of a DIVH protocol. It is plausible that our IsDAED approach is applicable for other infectious disease.

Environmental factors and spatiotemporal distribution characteristics of the global outbreaks of the highly pathogenic avian influenza H5N1.

The spread of highly pathogenic avian influenza H5N1 has posed a major threat to global public health. Understanding the spatiotemporal outbreak characteristics and environmental factors of H5N1 outbreaks is of great significance for the establishment of effective prevention and control systems. The time and location of H5N1 outbreaks in poultry and wild birds officially confirmed by the World Organization for Animal Health from 2005 to 2019 were collected. Spatial autocorrelation analysis and multidistance spatial agglomeration analysis methods were used to analyze the global outbreak sites of H5N1. Combined with remote sensing data, the correlation between H5N1 outbreaks and environmental factors was analyzed using binary logistic regression methods. We analyzed the correlation between the H5N1 outbreak and environmental factors and finally made a risk prediction for the global H5N1 outbreaks. The results show that the peak of the H5N1 outbreaks occurs in winter and spring. H5N1 outbreaks exhibit aggregation, and a weak aggregation phenomenon is noted on the scale close to 5000 km. Water distance, road distance, railway distance, wind speed, leaf area index (LAI), and specific humidity were protective factors for the outbreak of H5N1, and the odds ratio (OR) were 0.985, 0.989, 0.995, 0.717, 0.832, and 0.935, respectively. Temperature was a risk factor with an OR of 1.073. The significance of these ORs was greater than 95%. The global risk prediction map was obtained. Given that the novel coronavirus (COVID-19) is spreading globally, the methods and results of this study can provide a reference for studying the spread of COVID-19.

Comparative early results of a robotics-assisted endoscope holder in single port thoracoscopic surgery in the era of COVID-19.

BACKGROUND: Innovations in surgical instruments have made single-port surgery more widely accepted and lead to a reduced demand for surgical assistants. As COVID-19 has ravaged the world, maintaining minimum medical staffing requirements and proper social distancing have become major topics of interest. We sought to evaluate the feasibility of applying the unisurgeon approach in single-port video-assisted thoracoscopic surgery aided by a robotic camera holder. METHODS: Operative time, blood loss, setup time, postoperative hospital stays, and the number of participating surgeons in single-port video-assisted thoracoscopic lung resections were gathered for investigation after the introduction of the ENDOFIXexo robotic endoscope holder system. In this cohort, we collected 213 patients who underwent single port video thoracoscope surgery, including 57 patients underwent robotic endoscope arm assisted surgery and case-matched 52 patients in the robotic arm-assisted group with patients in the human-assisted group through propensity score-matched analysis. RESULTS: In wedge resection, a single surgeon was able to completely operate on all lobes of target lesions. However, for anatomical resections, namely segmentectomy, the success rate was 95%, and for lobectomy, the success rate was only 64%. No significant differences between setup times, blood loss, or operative times between the two groups were observed. CONCLUSIONS: When an experienced uniport surgeon is assisted by a robotic endoscope holder, wedge resection is the most suitable procedure to be performed through unisurgeon single-port video-assisted thoracoscopic surgery without increasing setup time, operative time, or short-term complications. Verification of the technique's applicability for use in anatomic resections requires further investigation.

Are gritty students academically engaged in math and science?

This research examines the cross-cultural differences on triarchic model of grit (TMG) dimensions (i.e., perseverance of effort, consistency of interests, and adaptability to situations) and the associations of grit with academic engagement in Math and Science among secondary school students in one secondary school in Hong Kong (n = 101; M age = 12.44; SD = .60), nine secondary schools in Philippines (n = 575; Mage = 14.66; SD = .83), and two secondary schools in mainland China (n = 710; Mage = 13.39; SD = .56). Result of structural equation modeling via maximum likelihood estimation approach demonstrated that although all TMG dimensions were related to higher engagement in Math and Science, adaptability served as the strongest predictor of these outcomes even after controlling for the participants' cultural settings and conscientiousness. Consistency served as the weakest correlate of engagement outcomes. Conscientiousness, settings, and TMG dimensions explained 46% and 50% of the variance in Math and Science academic engagement respectively. These results provide additional evidence regarding the generalizability of TMG in non-Western societies. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Value of the Neutrophil-Lymphocyte Ratio in Predicting COVID-19 Severity: A Meta-analysis.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is highly contagious and continues to spread rapidly. However, there are no simple and timely laboratory techniques to determine the severity of COVID-19. In this meta-analysis, we assessed the potential of the neutrophil-lymphocyte ratio (NLR) as an indicator of severe versus nonsevere COVID-19 cases. METHODS: A search for studies on the NLR in severe and nonsevere COVID-19 cases published from January 1, 2020, to July 1, 2021, was conducted on the PubMed, EMBASE, and Cochrane Library databases. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR), and area under the curve (AUC) analyses were done on Stata 14.0 and Meta-disc 1.4 to assess the performance of the NLR. RESULTS: Thirty studies, including 5570 patients, were analyzed. Of these, 1603 and 3967 patients had severe and nonsevere COVID-19, respectively. The overall sensitivity and specificity were 0.82 (95% confidence interval (CI), 0.77-0.87) and 0.77 (95% CI, 0.70-0.83), respectively; positive and negative correlation ratios were 3.6 (95% CI, 2.7-4.7) and 0.23 (95% CI, 0.17-0.30), respectively; DOR was 16 (95% CI, 10-24), and the AUC was 0.87 (95% CI, 0.84-0.90). CONCLUSION: The NLR could accurately determine the severity of COVID-19 and can be used to identify patients with severe disease to guide clinical decision-making.

The signal pathways and treatment of cytokine storm in COVID-19.

The Coronavirus Disease 2019 (COVID-19) pandemic has become a global crisis and is more devastating than any other previous infectious disease. It has affected a significant proportion of the global population both physically and mentally, and destroyed businesses and societies. Current evidence suggested that immunopathology may be responsible for COVID-19 pathogenesis, including lymphopenia, neutrophilia, dysregulation of monocytes and macrophages, reduced or delayed type I interferon (IFN-I) response, antibody-dependent enhancement, and especially, cytokine storm (CS). The CS is characterized by hyperproduction of an array of pro-inflammatory cytokines and is closely associated with poor prognosis. These excessively secreted pro-inflammatory cytokines initiate different inflammatory signaling pathways via their receptors on immune and tissue cells, resulting in complicated medical symptoms including fever, capillary leak syndrome, disseminated intravascular coagulation, acute respiratory distress syndrome, and multiorgan failure, ultimately leading to death in the most severe cases. Therefore, it is clinically important to understand the initiation and signaling pathways of CS to develop more effective treatment strategies for COVID-19. Herein, we discuss the latest developments in the immunopathological characteristics of COVID-19 and focus on CS including the current research status of the different cytokines involved. We also discuss the induction, function, downstream signaling, and existing and potential interventions for targeting these cytokines or related signal pathways. We believe that a comprehensive understanding of CS in COVID-19 will help to develop better strategies to effectively control immunopathology in this disease and other infectious and inflammatory diseases.

Sensitive and Easy-Read CRISPR Strip for COVID-19 Rapid Point-of-Care Testing.

Rapid and clinically sensitive detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) play an important role in the contact tracing and containment of the COVID-19 pandemic. A recently developed field-deployable clustered regularly interspaced short palindromic repeats (CRISPR) detection assay with lateral flow strips shows promise for point-of-care detection of SARS-CoV-2. However, the limit of detection of paper strip-based assays (10-100 copies/µL) is much lower than that of fluorescence-based detection methods. In this study, we developed an easy-readout and sensitive enhanced (ERASE) strip to visualize the results of CRISPR detection and improve the sensitivity to 1 copy/µL with an unambiguous easy-read result. Using 649 clinical samples from blind specimens collected from patients in China, we validated our ERASE assay for SARS-CoV-2 RNA detection with 90.67% positive predictive agreement and 99.21% negative predictive agreement. In conclusion, our study provided a customized CRISPR strip for use in a simple, rapid, ultrasensitive, and highly specific assay for SARS-CoV-2 detection. (Clinical Trial Registration number: 2020-008-01; [2020]IEC(ZD01); PJ-NBEY-2020-009-01; 2020#34).

Pre-optimized phage therapy on secondary Acinetobacter baumannii infection in four critical COVID-19 patients.

Phage therapy is recognized as a promising alternative to antibiotics in treating pulmonary bacterial infections, however, its use has not been reported for treating secondary bacterial infections during virus pandemics such as coronavirus disease 2019 (COVID-19). We enrolled 4 patients hospitalized with critical COVID-19 and pulmonary carbapenem-resistant Acinetobacter baumannii (CRAB) infections to compassionate phage therapy (at 2 successive doses of 109 plaque-forming unit phages). All patients in our COVID-19-specific intensive care unit (ICU) with CRAB positive in bronchoalveolar lavage fluid or sputum samples were eligible for study inclusion if antibiotic treatment failed to eradicate their CRAB infections. While phage susceptibility testing revealed an identical profile of CRAB strains from these patients, treatment with a pre-optimized 2-phage cocktail was associated with reduced CRAB burdens. Our results suggest the potential of phages on rapid responses to secondary CRAB outbreak in COVID-19 patients.

Spatial distribution characteristics of the COVID-19 pandemic in Beijing and its relationship with environmental factors.

Investigating the spatial distribution characteristics of the coronavirus disease 2019 (COVID-19) and exploring the influence of environmental factors that drive it is the basis for formulating rational and efficient prevention and control countermeasures. Therefore, this study aims to analyze the spatial distribution characteristics of COVID-19 pandemic in Beijing and its relationship with the environmental factors. Based on the incidences of new local COVID-19 cases in Beijing from June 11 to July 5, the spatial clustering characteristics of the COVID-19 pandemic in Beijing was investigated using spatial autocorrelation analysis. The relation between COVID-19 cases and environmental factors was assessed using the Spearman correlation analysis. Finally, geographically weighted regression (GWR) was applied to explore the influence of environmental factors on the spatial distribution of COVID-19 cases. The results showed that the development of COVID-19 pandemic in Beijing from June 11 to July 5 could be divided into two stages. The first stage was the outward expansion from June 11 to June 21, and the second stage (from June 22 to July 5) was the growth of the transmission in areas with existing previous cases. In addition, there was a ring of low value clusters around the Xinfadi market. This area was the key area for prevention and control. Population density and distance to Xinfadi market were the most critical factors that explained the pandemic development. The findings of this study can provide useful information for the global fighting against COVID-19.

Risk factors for predicting mortality of COVID-19 patients: A systematic review and meta-analysis.

BACKGROUND: Early and accurate prognosis prediction of the patients was urgently warranted due to the widespread popularity of COVID-19. We performed a meta-analysis aimed at comprehensively summarizing the clinical characteristics and laboratory abnormalities correlated with increased risk of mortality in COVID-19 patients. METHODS: PubMed, Scopus, Web of Science, and Embase were systematically searched for studies considering the relationship between COVID-19 and mortality up to 4 June 2020. Data were extracted including clinical characteristics and laboratory examination. RESULTS: Thirty-one studies involving 9407 COVID-19 patients were included. Dyspnea (OR = 4.52, 95%CI [3.15, 6.48], P < 0.001), chest tightness (OR = 2.50, 95%CI [1.78, 3.52], P<0.001), hemoptysis (OR = 2.00, 95%CI [1.02, 3.93], P = 0.045), expectoration (OR = 1.52, 95%CI [1.17, 1.97], P = 0.002) and fatigue (OR = 1.27, 95%CI [1.09, 1.48], P = 0.003) were significantly related to increased risk of mortality in COVID-19 patients. Furthermore, increased pretreatment absolute leukocyte count (OR = 11.11, 95%CI [6.85,18.03], P<0.001) and decreased pretreatment absolute lymphocyte count (OR = 9.83, 95%CI [6.72, 14.38], P<0.001) were also associated with increased mortality of COVID-19. We also compared the mean value of them between survivors and non-survivors, and found that non-survivors showed significantly raise in pretreatment absolute leukocyte count (WMD: 3.27×109/L, 95%CI [2.34, 4.21], P<0.001) and reduction in pretreatment absolute lymphocyte count (WMD = -0.39×109/L, 95%CI [-0.46, -0.33], P<0.001) compared with survivors. The results of pretreatment lactate dehydrogenase (LDH), procalcitonin (PCT), D-Dimer and ferritin showed the similar trend with pretreatment absolute leukocyte count. CONCLUSIONS: Among the common symptoms of COVID-19 infections, fatigue, expectoration, hemoptysis, dyspnea and chest tightness were independent predictors of death. As for laboratory examinations, significantly increased pretreatment absolute leukocytosis count, LDH, PCT, D-Dimer and ferritin, and decreased pretreatment absolute lymphocyte count were found in non-survivors, which also have an unbeneficial impact on mortality among COVID-19 patients. Motoring these indicators during the hospitalization plays a very important role in predicting the prognosis of patients.

[Dynamic Changes of CT Findings in Pneumonia Patients with Coronavirus Disease 19].

OBJECTIVE: The chest CT findings of the pneumonia patients with coronavirus disease 19 (COVID-19) were summarized to provide an auxiliary diagnostic basis for the early detection of infected patients. METHODS: Clinical data and CT images of 23 patients diagnosed with COVID-19 in West China Hospital of Sichuan University were retrospectively collected, and the chest CT findings were summarized and analyzed. RESULT: Of the 23 patients, 56.5% (13/23) had bilateral disease, 69.6% (16/23) had lesions distributed along the bronchovascular bundle, 65.2% (15/23) had lesions distributed periphery, 82.6% (19/23) involved in the basal segment of lower lobe, 82.6% (19/23) had ground-glass opacities, 30.4% (7/23) had ground-glass opacities with consolidation, 26.1% (6/23) had reticular changes. In the stage of disease progression, 54.6% (6/11) had an increased number of lesions, and 63.6% (7/11) had the scope of lesions enlarged and density increased. In the remission stage, 25.0% (4/16) had reduced number of lesions, 81.3% (13/16) had scope of lesions reduced, 62.5% (10/16) had density of lesions decreased, and 37.5% (6/16) had fibrosis. CONCLUSIONS: As an important diagnostic examination method for COVID-19, CT is conducive to the rapid diagnosis of the disease in patients with epidemiological history.

Decreased T cell populations contribute to the increased severity of COVID-19.

BACKGROUND: We observe changes of the main lymphocyte subsets (CD16+CD56、CD19、CD3、CD4、and CD8) in COVID-19-infected patients and explore whether the changes are associated with disease severity. METHODS: One-hundred and fifty-four cases of COVID-19-infected patients were selected and divided into 3 groups (moderate group, severe group and critical group). The flow cytometry assay was performed to examine the numbers of lymphocyte subsets. RESULTS: CD3+, CD4+ and CD8 + T lymphocyte subsets were decreased in COVID-19-infected patients. Compared with the moderate group and the sever group, CD3+, CD4+ and CD8+ T cells in the critical group decreased greatly (P < 0.001, P = 0.005 or P = 0.001). CONCLUSIONS: Reduced CD3+, CD4+, CD8+ T lymphocyte counts may reflect the severity of the COVID-19. Monitoring T cell changes has important implications for the diagnosis and treatment of severe patients who may become critically ill.