Heterologous Immunity Between SARS-CoV-2 and Pathogenic Bacteria.

Heterologous immunity, when the memory T cell response elicited by one pathogen recognizes another pathogen, has been offered as a contributing factor for the high variability in coronavirus disease 2019 (COVID-19) severity outcomes. Here we demonstrate that sensitization with bacterial peptides can induce heterologous immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) derived peptides and that vaccination with the SARS-CoV-2 spike protein can induce heterologous immunity to bacterial peptides. Using in silico prediction methods, we identified 6 bacterial peptides with sequence homology to either the spike protein or non-structural protein 3 (NSP3) of SARS-CoV-2. Notwithstanding the effects of bystander activation, in vitro co-cultures showed that all individuals tested (n=18) developed heterologous immunity to SARS-CoV-2 peptides when sensitized with the identified bacterial peptides. T cell recall responses measured included cytokine production (IFN-γ, TNF, IL-2), activation (CD69) and proliferation (CellTrace). As an extension of the principle of heterologous immunity between bacterial pathogens and COVID-19, we tracked donor responses before and after SARS-CoV-2 vaccination and measured the cross-reactive T cell responses to bacterial peptides with similar sequence homology to the spike protein. We found that SARS-CoV-2 vaccination could induce heterologous immunity to bacterial peptides. These findings provide a mechanism for heterologous T cell immunity between common bacterial pathogens and SARS-CoV-2, which may explain the high variance in COVID-19 outcomes from asymptomatic to severe. We also demonstrate proof-of-concept that SARS-CoV-2 vaccination can induce heterologous immunity to pathogenic bacteria derived peptides.

Robust Antibody and T Cell Responses in COVID-19 Patients Six Months After Infection (preprint)

Determining the longevity of natural immunity after SARS-CoV-2 infection is critical for understanding immune protection and optimizing vaccine design. Over six months have been passed since the emergence of COVID-19 in China. We evaluated humoral and cellular responses in 418 patients six months after infection. 95.9% and 98.1% of the patients maintained SARS-CoV-2-specific IgG and neutralizing antibodies. All severe patients were positive for IgG and neutralizing antibodies and had significantly higher titers than mild and moderate patients as well as asymptomatic individuals. The patients had a more robust SARS-CoV-2-specific CD4+ T cell response than CD8+ T cells six months after infection. Unexpectedly, sustained immune activation was observed, which displayed as the evaluated proinflammatory monocytes, non-classical NK cells, CD4+ Treg cells, and activated CD4+ T cells. Our findings indicate that SARS-CoV-2 gives rise to persisting and robust protective immunity, which provides a promising sign for prevention from reinfection and vaccination strategy.Funding: This work was supported by grants from the Natural Science Foundation of China (81773494 to M.J.M.), the National Major Project for Control and Prevention of Infectious Disease of China (2017ZX10303401-006 to M.J.M.), the Special National Project on Investigation of Basic Resources of China (2019FY101502 to M.J.M.).Conflict of Interest: The authors declare no competing interests.Ethical Approval: All patients provided written informed consent. The study was conducted following the Declaration of Helsinki, and the Institutional Review Board of the Academy of Military Medical Sciences approved the study protocol (IRB number: AF/SC-08/02.46).

Prevalence of acute liver injury and hypertransaminemia in patients with COVID-19: a protocol for a systematic review.

INTRODUCTION: COVID-19 has spread rapidly in China and around the world. Published studies have revealed that some patients with COVID-19 had abnormal liver function in laboratory tests. However, the results were inconsistent and the analysis of epidemiological data stratified by the severity of COVID-19 was not available in previous meta-analyses. Furthermore, these meta-analyses were suspected of overestimating the incidence of liver injury in patients with COVID-19 because some studies considered transaminase elevation as liver injury, which might partially result from cardiac and muscle injury. This systematic review aims to enrol published literatures related to COVID-19 without language restriction, analyse the data based on the severity of the COVID-19 and explore the impact of varied definitions of liver injury on the incidence of liver injury. METHODS AND ANALYSIS: We have conducted a preliminary search on PubMed and Excerpta Medica Database on 13 April 2020, for the studies published after December 2019 on the prevalence of acute liver injury and hypertransaminemia in patients with COVID-19. Two reviewers will independently screen studies, extract data and assess the risk of bias. We will estimate the pooled incidence of hypertransaminemia and acute liver injury in patients with COVID-19 by using the random-effects model. The I² test will be used to identify the extent of heterogeneity. Publication bias will be assessed by funnel plot and performing the Begg's and Egger's test if adequate studies are available. We will perform a risk of bias assessment using the Joanna Briggs Institute's critical appraisal checklist. ETHICS AND DISSEMINATION: Since this study will be based on the published data, it does not require ethical approval. The final results of this study will be published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42020179462.

Analysis of the influence of the psychology changes of fear induced by the COVID-19 epidemic on the body: COVID-19.

In this paper, the theory of " Fear injury kidney " in traditional Chinese medicine is systematically reviewed, and it is found that long-term or excessive psychological changes of fear are likely to damage kidney qi and kidney essence. On this basis, the psychological studies of patients, medical staff and the public during the COVID-19 epidemic in China were analyzed, and fear psychology was found to be prevalent among all kinds of people. Modern researches on "Fear injury kidney" have also found that long-term or excessive fear could cause changes in the neuro-endocrine-immune system, which can induce diseases or susceptibility to some diseases. Therefore, during or after the prevalence of COVID-19, different groups of people may have emotional reactions such as stress and fear, which should be paid long-term attention, and the influence of fear on the body cannot be ignored. According to the change rule of psychological state under stress reaction, we should actively respond to and take psychological crisis intervention measures in time to reduce the harm of psychological stress to the body.

Changes in CT manifestations of patients with mild to moderate coronavirus disease 2019 in a Fangcang Shelter Hospital (preprint)

Objectives: To provide a reference for CT imaging changes for patients discharged from a Fangcang shelter hospital, a large-scale, temporary hospital for the centralized treatment of patients with mild to moderate Coronavirus disease 2019 (COVID-19) to provide essential functions (isolation, triage, basic medical care, frequent monitoring and rapid referral, essential living and social engagement) to them..Methods: Patients with mild to moderate COVID-19 admitted to the Wuchang Fangcang Shelter Hospital who had undergone pre-discharge and previous CT scans were included. Changes in the CT imaging features were defined as progression, no change, improvement or recovery. Basic patient information was obtained, and imaging signs were compared between the two CT scans.Results: A total of 83 patients were included. The median age was 53 years old. The course of disease was 28.3±10.7 days. CT imaging changes indicated progression, no change, improvement, and recovery in 3, 12, 66, and 2 patients, respectively. Between the two CT scans, the imaging signs showed a significant reduction in consolidation, a significant increase in fibrosis, and a reduction or / and thinning of ground-glass opacities. None of the patients showed signs of deterioration on follow-up and thus did not need to return to the hospital for treatment.Conclusion: In the COVID-19 Fangcang shelter hospital, given the shortage of medical staff and lack of medical resources, CT imaging diagnostic methods can be used to accurately discharge patients who had met the discharge criteria for isolation and observation from the Fangcang Shelter Hospital.