Seasonal coronaviruses and SARS-CoV-2: effects of preexisting immunity during the COVID-19 pandemic

Although the coronavirus disease 2019 (COVID-19) epidemic is still ongoing, vaccination rates are rising slowly and related treatments and drugs are being developed. At the same time, there is increasing evidence of preexisting immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in humans, mainly consisting of preexisting antibodies and immune cells (including T cells and B cells). The presence of these antibodies is mainly due to the seasonal prevalence of four common coronavirus types, especially OC43 and HKU1. The accumulated relevant evidence has suggested that the target of antibodies is mainly the S2 subunit of S protein, followed by evolutionary conservative regions such as the nucleocapsid (N) protein. Additionally, preexisting memory T and B cells are also present in the population. Preexisting antibodies can help the body protect against SARS-CoV-2 infection, reduce the severity of COVID-19, and rapidly increase the immune response post-infection. These multiple effects can directly affect disease progression and even the likelihood of death in certain individuals. Besides the positive effects, preexisting immunity may also have negative consequences, such as antibody-dependent enhancement (ADE) and original antigenic sin (OAS), the prevalence of which needs to be further established. In the future, more research should be focused on evaluating the role of preexisting immunity in COVID-19 outcomes, adopting appropriate policies and strategies for fighting the pandemic, and vaccine development that considers preexisting immunity.     

Development and validation of an individualized nomogram for early prediction of the duration of SARS-CoV-2 shedding in COVID-19 patients with non-severe disease

With the number of cases of coronavirus disease-2019(COVID-19) increasing rapidly, the World Health Organization(WHO) has recommended that patients with mild or moderate symptoms could be released from quarantine without nucleic acid retesting, and self-isolate in the community. This may pose a potential virus transmission risk. We aimed to develop a nomogram to predict the duration of viral shedding for individual COVID-19 patients. This retrospective multicentric study enrolled 135 patients as a training cohort and 102 patients as a validation cohort. Significant factors associated with the duration of viral shedding were identified by multivariate Cox modeling in the training cohort and combined to develop a nomogram to predict the probability of viral shedding at 9, 13, 17, and 21 d after admission. The nomogram was validated in the validation cohort and evaluated by concordance index(C-index), area under the curve(AUC), and calibration curve. A higher absolute lymphocyte count(P=0.001) and lymphocyte-to-monocyte ratio(P=0.013) were correlated with a shorter duration of viral shedding, while a longer activated partial thromboplastin time(P=0.007) prolonged the viral shedding duration. The C-indices of the nomogram were 0.732(95% confidence interval(CI): 0.685-0.777) in the training cohort and 0.703(95% CI: 0.642-0.764) in the validation cohort. The AUC showed a good discriminative ability(training cohort: 0.879, 0.762, 0.738, and 0.715 for 9, 13, 17, and 21 d; validation cohort: 0.855, 0.758, 0.728, and 0.706 for 9, 13, 17, and 21 d), and calibration curves were consistent between outcomes and predictions in both cohorts. A predictive nomogram for viral shedding duration based on three easily accessible factors was developed to help estimate appropriate self-isolation time for patients with mild or moderate symptoms, and to control virus transmission.     

Structural and physiological changes of the human body upon SARS-CoV-2 infection

Since December 2019, the novel coronavirus(severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)) has spread to many countries around the world, developing into a global pandemic with increasing numbers of deaths reported worldwide. To data, although some vaccines have been developed, there are no ideal drugs to treat novel coronavirus pneumonia(coronavirus disease 2019(COVID-19)). By examining the structure of the coronavirus and briefly describing its possible pathogenesis based on recent autopsy reports conducted by various teams worldwide, this review analyzes the possible structural and functional changes of the human body upon infection with SARS-CoV-2. We observed that the most prominent pathological changes in COVID-19 patients are diffuse alveolar damage(DAD) of the lungs and microthrombus formation,resulting in an imbalance of the ventilation/perfusion ratio and respiratory failure. Although direct evidence of viral infection can also be found in other organs and tissues, the viral load is relatively small. The conclusion that the injuries of the extrapulmonary organs are directly caused by the virus needs further investigation.     

Impact of COVID-19 pandemic on the pregnancy outcomes of women undergoing assisted reproductive techniques (ARTs): a systematic review and meta-analysis

The global outbreak of the coronavirus disease 2019 (COVID-19) led to the suspension of most treatments with assisted reproductive technique (ART). However, with the recent successful control of the pandemic in China, there is an urgent public need to resume full reproductive care. To determine whether the COVID-19 pandemic had any adverse effects on female fertility and the pregnancy outcomes of women undergoing ART, a systematic review and meta-analysis was conducted using the electronic Chinese and English databases. Dichotomous outcomes were summarized as prevalence, and odds ratios (ORs) and continuous outcomes as standardized mean difference (SMD) with 95% confidence interval (CI). The risk of bias and subgroup analyses were assessed using Stata/SE 15.1 and R 4.1.2. The results showed that compared with women treated by ART in the pre-COVID-19 time frame, women undergoing ART after the COVID-19 pandemic exhibited no significant difference in the clinical pregnancy rate (OR 1.07, 95% CI 0.97 to 1.19; I ²=0.0%), miscarriage rate (OR 0.95, 95% CI 0.79 to 1.14; I ²=38.4%), embryo cryopreservation rate (OR 2.90, 95% CI 0.17 to 48.13; I ²=85.4%), and oocyte cryopreservation rate (OR 0.30, 95% CI 0.03 to 3.65; I ²=81.6%). This review provided additional evidence for gynecologists to guide the management of women undergoing ART treatment during the COVID-19 pandemic timeframe.     

ADP-ribosylhydrolases: from DNA damage repair to COVID-19

Adenosine diphosphate(ADP)-ribosylation is a unique post-translational modification that regulates many biological processes,such as DNA damage repair.During DNA repair,ADP-ribosylation needs to be reversed by ADP-ribosylhydrolases.A group of ADP-ribosylhydrolases have a catalytic domain,namely the macrodomain,which is conserved in evolution from prokaryotes to humans.Not all macrodomains remove ADP-ribosylation.One set of macrodomains loses enzymatic activity and only binds to ADP-ribose(ADPR).Here,we summarize the biological functions of these macrodomains in DNA damage repair and compare the structure of enzymatically active and inactive macrodomains.Moreover,small molecular inhibitors have been developed that target macrodomains to suppress DNA damage repair and tumor growth.Macrodomain proteins are also expressed in pathogens,such as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).However,these domains may not be directly involved in DNA damage repair in the hosts or pathogens.Instead,they play key roles in pathogen replication.Thus,by targeting macrodomains it may be possible to treat pathogen-induced diseases,such as coronavirus disease 2019(COVID-19).     

Factors associated with a SARS-CoV-2 recurrence after hospital discharge among patients with COVID-19: systematic review and meta-analysis

Background: The proportion of recurrences after discharge among patients with coronavirus disease 2019 (COVID-19) was reported to be between 9.1% and 31.0%. Little is known about this issue, however, so we performed a meta-analysis to summarize the demographical, clinical, and laboratorial characteristics of non-recurrence and recurrence groups. Methods: Comprehensive searches were conducted using eight electronic databases. Data regarding the demographic, clinical, and laboratorial characteristics of both recurrence and non-recurrence groups were extracted, and quantitative and qualitative analyses were conducted. Results: Ten studies involving 2071 COVID-19 cases were included in this analysis. The proportion of recurrence cases involving patients with COVID-19 was 17.65% (between 12.38% and 25.16%) while older patients were more likely to experience recurrence (weighted mean difference (WMD)=1.67, range between 0.08 and 3.26). The time from discharge to recurrence was 13.38 d (between 12.08 and 14.69 d). Patients were categorized as having moderate severity (odds ratio (OR)=2.69, range between 1.30 and 5.58), while those with clinical symptoms including cough (OR=5.52, range between 3.18 and 9.60), sputum production (OR=5.10, range between 2.60 and 9.97), headache (OR=3.57, range between 1.36 and 9.35), and dizziness (OR=3.17, range between 1.12 and 8.96) were more likely to be associated with recurrence. Patients presenting with bilateral pulmonary infiltration and decreased leucocyte, platelet, and CD4⁺ T counts were at risk of COVID-19 recurrence (OR=1.71, range between 1.07 and 2.75; WMD=−1.06, range between −1.55 and −0.57, WMD=−40.39, range between −80.20 and −0.48, and WMD=−55.26, range between −105.92 and −4.60, respectively). Conclusions: The main factors associated with the recurrence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after hospital discharge were older age, moderate severity, bilateral pulmonary infiltration, laboratory findings including decreased leucocytes, platelets, and CD4⁺ T counts, and clinical symptoms including cough, sputum production, headache, and dizziness. These factors can be considered warning indicators for the recurrence of SARS-CoV-2 and might help the development of specific management strategies.     

Clinical characteristics and plasma antibody titer of patients with COVID-19 in Zhejiang,China

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which first affected humans in China on December 31, 2019 (Shi et al., 2020). Coronaviruses generally cause mild, self-limiting upper respiratory tract infections in humans, such as the common cold, pneumonia, and gastroenteritis (To et al., 2013; Berry et al., 2015; Chan et al., 2015). According to the Report of the World Health Organization (WHO)-China Joint Mission on COVID-19 (WHO, 2020), the case fatality rate of COVID-19 increases with age, while the rate among males is higher than that among females (4.7% and 2.8%, respectively). Since an effective vaccine and specific anti-viral drugs are still under development, passive immunization using the convalescent plasma (CP) of recovered COVID-19 donors may offer a suitable therapeutic strategy for severely ill patients in the meantime. So far, several studies have shown therapeutic efficacy of CP transfusion in treating COVID-19 cases. A pilot study first reported that transfusion of CP with neutralizing antibody titers above 1:640 was well tolerated and could potentially improve clinical outcomes through neutralizing viremia in severe COVID-19 cases (Chen et al., 2020). Immunoglobulin G (IgG) and IgM are the most abundant and important antibodies in protecting the human body from viral attack (Arabi et al., 2015; Marano et al., 2016). Our study aimed to understand the aspects of plasma antibody titer levels in convalescent patients, as well as assessing the clinical characteristics of normal, severely ill, and critically ill patients, and thus provide a basis for guiding CP therapy. We also hoped to find indicators which could serve as a reference in predicting the progression of the disease.     

Clinical and immune response characteristics among vaccinated persons infected with SARS-CoV-2 delta variant: a retrospective study

ObjectiveThis study aimed to observe the clinical and immune response characteristics of vaccinated persons infected with the delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Yangzhou, China.MethodsWe extracted the medical data of 129 patients with delta-variant infection who were admitted to Northern Jiangsu People’s Hospital (Yangzhou, China) between August and September, 2021. The patients were grouped according to the number of vaccine doses received into an unvaccinated group: a one-dose group and a two-dose group. The vaccine used was SARS-CoV-2-inactivated vaccine developed by Sinovac. We retrospectively analyzed the patients’ epidemiological, clinical, laboratory, and imaging data.ResultsAlmost all patients with delta-variant infection in Yangzhou were elderly, and patients with severe/critical illness were over 70 years of age. The rates of severe/critical illness (P=0.006), fever (P=0.025), and dyspnea (P=0.045) were lower in the two-dose group than in the unvaccinated group. Compared to the unvaccinated group, the two-dose group showed significantly higher lymphocyte counts and significantly lower levels of C-reactive protein (CRP), interleukin-6 (IL-6), and D-dimer during hospitalization and a significantly higher positive rate of immunoglobulin G (IgG) antibodies at admission (all P<0.05). The cumulative probabilities of hospital discharge and negative virus conversion were also higher in the two-dose group than in the unvaccinated group (P<0.05).ConclusionsTwo doses of the SARS-CoV-2-inactivated vaccine were highly effective at limiting symptomatic disease and reducing immune response, while a single dose did not seem to be effective.     

Weathering the storm: COVID-19 infection in patients with hematological malignancies

The coronavirus disease 2019 (COVID-19) is an emerging infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Within a matter of months, this highly contagious novel virus has led to a global outbreak and is still spreading rapidly across continents. In patients with COVID-19, underlying chronic diseases and comorbidities are associated with dismal treatment outcomes. Owing to their immunosuppressive status, patients with hematological malignancies (HMs) are at an increased risk of infection and have a worse prognosis than patients without HMs. Accordingly, intensive attention should be paid to this cohort. In this review, we summarize and analyze specific clinical manifestations for patients with coexisting COVID-19 and HMs. Furthermore, we briefly describe customized management strategies and interventions for this susceptible cohort. This review is intended to guide clinical practice.     

Research on the construction and application of teacher-student interaction evaluation system for smart classroom in the post COVID-19

Smart classroom (SC) is an important embodiment of the new teaching mode in online and offline integration in the COVID-19. At present, the research on the evaluation system of teacher-student interaction (TSI) in SC lacks evaluation system to guide the development of students’ higher order thinking (HOT). This evaluation system of TSI was established through grounded theory, Delphi method and analytic hierarchy process. The evaluation system for TSI considered the support of intelligent technology for various indicators and the development of students’ HOT. The evaluation system included 4 first level indicators, 16 s level indicators and 44 third level indicators. The evaluation system had been comprehensively evaluated the TSI activities, which was conducive to the development of students’ HOT.Data availabilityData used in this research are available upon request from the corresponding author.     

Understanding effects of COVID-19 on undergraduate academic stress,motivation and coping over time

The rapid and unprecedented shift from face-to-face instruction to remote online learning as a consequence of the COVID-19 pandemic had a substantial impact on teaching and learning in Higher Education: students had to adapt to a new way of learning, away from typical campus settings and their peers, and to new forms of assessments. This study examined academic stress, learning strategies, motivation and ways of coping from a sample of 177 unique students from a large London university, collecting primary data via survey at three time points during the academic year 2020/21 when teaching was remote and online only. Our findings show how patterns in academic stress, learning strategies, motivation and coping vary over the course of the academic year giving novel insight into how student learning and adaptation to the situation changed over time. We also report on differences in these patterns according to year group and for those students who are the first-in-family to attend university and those who are not. Based on these findings we identify priority areas where higher education institutions should support undergraduate students and provide evidence that some groups of students may need more and targeted support to secure their ongoing learning and well-being.     

The Potential Impact of COVID-19 on Student Learning and How Schools Can Respond

There is no denying the impact that the coronravirus disease (COVID-19) outbreak has had on many aspects of our lives. This article looks at the potential impact of COVID-19 on student learning as schools abruptly morphed into virtual learning environments using data from several instructional, practice, and assessment solutions offered by Renaissance. First, three hypothetical learning scenarios are considered using normative data from Star assessments to explore the potential impact on reading and math test performace. Next, data on Focus Skills are used to highlight which grades may have missed the most foundational math and reading content if instruction was stopped or reduced. Last, data from two of Renaissance's practice tools are used to evaluate whether students were practicing key skills following school closures. The article concludes that academic decline will likely occur but may be tempered by the increased use of practice tools; effects may look different for math and reading; and may impact grades and schools differently. As such, schools may need to leverage decision-making frameworks, such as the Multi-tiered Systems of Support/Response-to-Intervention (MTSS/RTI) framework, more than ever to identify needs and target instruction where it matters most when school begins in fall 2020.     

非医学类高校防控新冠疫情措施的探析

新型冠状病毒是一种新发现的传染性很强的病毒,病毒的潜伏期长,全球存在很多被感染后的无症状者和复阳者。高校人员集中、生源广泛、学生活动范围大、普遍实行寄宿制、大班教学等特点,加之非医学类高校对健康教育及基础医疗知识的普及和实践不够重视,学生在面对突发公共卫生事件时缺乏基本的防控意识和自救、互救能力。因此这类院校更要积极做好新型冠状病毒肺炎疫情的防控。根据目前非医学类高校在突发公共卫生事件防控方面存在的问题,结合新冠病毒的感染、传播特点,从设立长效应急队伍或机构、制定行之有效地防控和应急预案,在落实师生健康教育课程、监测预警、建设医疗应急队伍和及时进行疫后心理疏导等方面提出了对策和建议。     

新冠肺炎疫情下大学生心态变化及引导策略

当前中国新冠肺炎疫情防控工作已从应急状态转为常态化状态.调查显示,学生在疫情下的心态变化呈现出消极情绪明显缓解、思想认知趋于理性、行为表达积极正向、"四个自信"更加坚定的总体特征.但是,由于疫情所引发的学生心态问题及成长困境也不容忽视,高校应结合疫情防控工作对大学生进行针对性和实效性的引导,发挥高校思想政治教育在组织动...     

SARS及其他几种冠状病毒密码子使用偏性的位点差异

分析了SARS冠状病毒以及其他5种冠状病毒基因编码起始区与终止区的密码子使用偏性.结果表明,冠状病毒基因组的稀有密码子倾向于出现在编码起始区和终止区附近.起始区的这种倾向性对冠状病毒基因的表达具有负性调控作用,可以用"稀有密码子调控假说"解释.终止区的这种倾向性表明,这些出现在终止区的稀有密码子对基因的表达也有负性调节作用.研究结果同时暗示了"稀有密码子调控假说"不仅适用于细菌,而且还适用于某些病毒基因组.     

公共危机治理: 一种能力建设的议程

伴随中国社会治理功能的社区化,社区已成为践行基层社会治理的关键主体。在公共危机治理中,社区工作的功能价值日益凸显。社区工作介入公共危机治理的独特优势,不仅根植于社区自身的多重特性之中,如社区是居民利益攸关的社会生活共同体,是危机防控的初级现场等,还与社区工作有着专业化、行业化、系统化机制的支撑相关。在参与公共危机治理中,社区工作仍然面临系列问题。应建立、健全与公共危机治理相配套的社区体制机制,建构并形成由社区工作主导或参与的应急机制或平台,使社区工作优势得以更充分的发挥。     

疫情下高校毕业生的学习与就业状况研究

2020年春季学期是高校毕业生学习、求职与深造的关键时期,新冠肺炎疫情影响全球经济和社会生活,也对高校毕业生的职业生涯发展产生冲击。基于江苏省9535份问卷数据发现,在学业方面,毕业生对最后一个学期尚有多元化学习期待,由于疫情影响,他们大多只能居家学习,毕业论文/设计完成进度不理想,普遍担忧能否如期毕业。面临深造还是求...     

新冠肺炎疫情下高校大学生政治信任状况分析研究

新冠疫情在较短的时间里迅速蔓延世界各地,如何形成有效治理机制成为各国首要任务。相比西方国家,我国在党中央的指导下,协调各方部门、组织,极短的时间内控制住了疫情,彰显出了我国体制的优势,推动了内地高校大学生增强我国政治信任度。本文选取内地高校大学生为研究对象,采用多元回归方法分析新冠肺炎疫情下大学生政治信任现状以及影响大学生政治信任“分殊化”的主要因素,发现内地高校大学生对各级政府政治信任度呈现“差序格局”现象,对政治信任三个主要标的物的信任程度排列为:对政治制度信任程度>对政府机构信任程度>对政府工作人员信任程度,以此提出增强新时代大学生政治信任的路径选择。     

抗疫保教:教育技术的责任与担当

2020年新型冠状病毒肺炎疫情的爆发,使我国教育系统面临的突出矛盾表现为社会期盼教育系统不影响学生发展能尽量组织教学与师生不能到校之间的矛盾。发挥教育技术学科优势、主动介入解决矛盾是教育技术学科和教育技术人应有的责任和担当。教育技术特有的学科积淀和丰富的网络教学实践成果为解决当前教育的突出矛盾提供了可行性和可能性。疫情状态下一线教师开展网络教学应该注意转变教学观念、做好教学设计、设计好教学交互、实施分段分层教学、重视学生自主学习能力培养等五个方面的问题。从系统科学的视角,教育技术对促进教学变革也有其发挥作用的限度,理性认识教育技术的定位并解决好其擅长解决的问题是应该持有的立场。未来教育技术学科应当加快与教育学其他二级学科"深度融合",聚焦育人本位,共同推动智能时代的教育变革。