Longitudinal proteomic investigation of COVID-19 vaccination.

Although the development of COVID-19 vaccines has been a remarkable success, the heterogeneous individual antibody generation and decline over time are unknown and still hard to predict. In this study, blood samples were collected from 163 participants who next received two doses of an inactivated COVID-19 vaccine (CoronaVac®) at a 28-day interval. Using TMT-based proteomics, we identified 1,715 serum and 7,342 peripheral blood mononuclear cells (PBMCs) proteins. We proposed two sets of potential biomarkers (seven from serum, five from PBMCs) at baseline using machine learning, and predicted the individual seropositivity 57 days after vaccination (AUC = 0.87). Based on the four PBMC's potential biomarkers, we predicted the antibody persistence until 180 days after vaccination (AUC = 0.79). Our data highlighted characteristic hematological host responses, including altered lymphocyte migration regulation, neutrophil degranulation, and humoral immune response. This study proposed potential blood-derived protein biomarkers before vaccination for predicting heterogeneous antibody generation and decline after COVID-19 vaccination, shedding light on immunization mechanisms and individual booster shot planning.

Safe CO2 threshold limits for indoor long-range airborne transmission control of COVID-19.

CO2-based infection risk monitoring is highly recommended during the current COVID-19 pandemic. However, the CO2 monitoring thresholds proposed in the literature are mainly for spaces with fixed occupants. Determining CO2 threshold is challenging in spaces with changing occupancy due to the co-existence of quanta and CO2 remaining from previous occupants. Here, we propose a new calculation framework for deriving safe excess CO2 thresholds (above outdoor level), C t, for various spaces with fixed/changing occupancy and analyze the uncertainty involved. We categorized common indoor spaces into three scenarios based on their occupancy conditions, e.g., fixed or varying infection ratios (infectors/occupants). We proved that the rebreathed fraction-based model can be applied directly for deriving C t in the case of a fixed infection ratio (Scenario 1 and Scenario 2). In the case of varying infection ratios (Scenario 3), C t derivation must follow the general calculation framework due to the existence of initial quanta/excess CO2. Otherwise, C t can be significantly biased (e.g., 260 ppm) when the infection ratio varies greatly. C t can vary significantly based on specific space factors such as occupant number, physical activity, and community prevalence, e.g., 7 ppm for gym and 890 ppm for lecture hall, indicating C t must be determined on a case-by-case basis. An uncertainty of up to 6 orders of magnitude for C t was found for all cases due to uncertainty in emissions of quanta and CO2, thus emphasizing the role of accurate emissions data in determining C t.

Safety of inactivated SARS-CoV-2 vaccines in myasthenia gravis: A survey-based study.

Background: Vaccination remains the most effective measure to prevent SARS-CoV-2 infection and worse outcomes. However, many myasthenia gravis (MG) patients are hesitant to receive vaccine due to fear of worsening. Methods: MG patients were consecutively enrolled in two MG centers in North China. The "worsening" after vaccination was self-reported by MG patients, and severity was measured with a single simple question. The general characteristics and disease status immediately prior to the first dose were compared between the worsening and non-worsening groups. Independent factors associated with worsening were explored with multivariate regression analysis. Results: One hundred and seven patients were included. Eleven patients (10.3%) reported worsening after vaccination, including eight patients with mild or moderate worsening and three patients with severe worsening. Only one of them (0.9%) needed an escalation of immunosuppressive treatments. There were significant differences between the worsening and non-worsening groups in terms of Myasthenia Gravis Foundation of America classes immediately before the first dose and intervals since the last aggravation. Precipitating factors might contribute to the worsening in some patients. Logistic regression revealed that only interval since the last aggravation ≤6 months was associated with worsening after SARS-CoV-2 vaccination (P = 0.01, OR = 8.62, 95% CI: 1.93-38.46). Conclusion: SARS-CoV-2 vaccines (an overwhelming majority were inactivated vaccines) were found safe in milder Chinese MG patients who finished two doses. Worsening after vaccination was more frequently seen in patients who were presumed as potentially unstable (intervals since last aggravation ≤6 months). However, mild worsening did occur in patients who were presumed to be stable. Precipitating factors should still be sought and treated for better outcome.

Safety of inactivated SARS-CoV-2 vaccines in myasthenia gravis: A survey-based study

Background Vaccination remains the most effective measure to prevent SARS-CoV-2 infection and worse outcomes. However, many myasthenia gravis (MG) patients are hesitant to receive vaccine due to fear of worsening. Methods MG patients were consecutively enrolled in two MG centers in North China. The “worsening” after vaccination was self-reported by MG patients, and severity was measured with a single simple question. The general characteristics and disease status immediately prior to the first dose were compared between the worsening and non-worsening groups. Independent factors associated with worsening were explored with multivariate regression analysis. Results One hundred and seven patients were included. Eleven patients (10.3%) reported worsening after vaccination, including eight patients with mild or moderate worsening and three patients with severe worsening. Only one of them (0.9%) needed an escalation of immunosuppressive treatments. There were significant differences between the worsening and non-worsening groups in terms of Myasthenia Gravis Foundation of America classes immediately before the first dose and intervals since the last aggravation. Precipitating factors might contribute to the worsening in some patients. Logistic regression revealed that only interval since the last aggravation ≤6 months was associated with worsening after SARS-CoV-2 vaccination (P = 0.01, OR = 8.62, 95% CI: 1.93–38.46). Conclusion SARS-CoV-2 vaccines (an overwhelming majority were inactivated vaccines) were found safe in milder Chinese MG patients who finished two doses. Worsening after vaccination was more frequently seen in patients who were presumed as potentially unstable (intervals since last aggravation ≤6 months). However, mild worsening did occur in patients who were presumed to be stable. Precipitating factors should still be sought and treated for better outcome.

An acceptable methodological evaluation method of real-time fluorescent RT-PCR targeting SARS-CoV-2 (preprint)

Background: it is necessary to evaluate real-time fluorescent reverse-transcription PCR (RT-PCR) methods to detect the nucleic acids of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: considering lack of positive specimens in some particular locations in China, the specimens from healthy individuals were used to perform the methodology evaluations, in which the indexes were the differences of quantification cycle values (ΔCq) between human-derived internal reference control (IRC) genes of a specimen and quality control gene (QC). A series of experiments was conducted to evaluate various factors that might affect the results, such as types of virus transport media, methods of specimen pretreatment and template preparation, specimen vortex strength, specimen storage temperature, and duration. Results: it was better to store specimens in normal saline (NS) transport medium, release more virus particles from swabs by vortex mixing, extract nucleic acids with centrifugation methods, and perform amplification assays timely. The above-mentioned options and optimum conditions were further confirmed using SARS-CoV-2 pseudoviruses and positive clinical specimens. Conclusions: this study provides a solution for the accurate detection of SARS-CoV-2. Specifically, this study also indicates that the routine specimens from healthy individuals could be used to methodological evaluation of real-time fluorescent RT-PCR targeting SARS-CoV-2, of which the indexes were the ΔCq values.

Challenges for China's medical education in the coming post-COVID-19 era.

The year of 2020 has been overshadowed by the COVID-19 pandemic. Medical workers throughout China have played critical roles in battling severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) and saving lives. The whole of society has now fully realized the significance of medical workers and many began to think about medical education in China: How can we further improve medical education for the next generation of clinicians, medical scientists, nurses, public-health workers and administrators related to medical care, so that they are well prepared to meet societal needs for medical care in the ever-changing world? In this panel discussion, medical-education experts from several prominent medical schools in China gathered to discuss the reform and future development of China's medical education. Xiang Chen President of Xiangya School of Medicine, Vice President of Central South University, Changsha, China Baorong Chi Professor of Norman Bethune Health Science Center of Jilin University, Changchun, China Yiqun Hu Vice Chancellor of Shanghai Jiao Tong University School of Medicine, Shanghai, China Yang Ke Professor of Peking University Health Science Center, former Vice President of Peking University, Beijing, China Ming Kuang Vice President of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China Mengfeng Li President of Southern Medical University, Guangzhou, China Hongbing Shen President of Nanjing Medical University, Nanjing, China Xuehong Wan Professor of West China Medical Center, Vice President of Graduate School of Sichuan University, Chengdu, China Hong Yan President of Xi'an Jiaotong University Health Science Center, Vice President of Xi'an Jiaotong University, Xi'an, China Guoqiang Chen (Chair) Chancellor of Shanghai Jiao Tong University School of Medicine, Vice President of Shanghai Jiao Tong University, Shanghai, China.

Repercussions of clinical waste co-incineration in municipal solid waste incinerator during COVID-19 pandemic.

During coronavirus disease 2019 pandemic, the exponential increase in clinical waste (CW) generation has caused immense burden to CW treatment facilities. Co-incineration of CW in municipal solid waste incinerator (MSWI) is an emergency treatment method. A material flow model was developed to estimate the change in feedstock characteristics and resulting acid gas emission under different CW co-incineration ratios. The ash contents and lower heating values of the feedstocks, as well as HCl concentrations in flue gas showed an upward trend. Subsequently, 72 incineration residue samples were collected from a MSWI performing co-incineration (CW ratio <10 wt%) in Wuhan city, China, followed by 20 incineration residues samples from waste that were not co-incineration. The results showed that the contents of major elements and non-volatile heavy metals in the air pollution control residues increased during co-incineration but were within the reported ranges, whereas those in the bottom ashes revealed no significant changes. The impact of CW co-incineration at a ratio <10 wt% on the distribution of elements in the incineration residues was not significant. However, increase in alkali metals and HCl in flue gas may cause potential boiler corrosion. These results provide valuable insights into pollution control in MSWI during pandemic.

Computed tomography in coronavirus disease 2019: diagnosis and clinical significance

Objective To investigate the computed tomography (CT) features of the coronavirus disease 2019 (COVID-19) and the clinical significance, so as to improve our understanding of CT imaging of this disease. Methods The chest CT features of seven COVID-19 patients, who were diagnosed by virus nucleic acid test from Jan. 25 to Feb. 15, 2020 in Changhai Hospital of Naval Medical University (Second Military Medical University), were analyzed retrospectively. There were six males and one female, aged (51.1±18.8) years (range 29-75 years). All the seven patients received chest CT plain scan examimation. The CT images were interpreted by two experienced senior radiologists, and the distribution, location and density of lesions, number of involved lobes, air bronchogram, mediastinal lymphadenopathy and pleural effusion were analyzed. Results The average time from onset of symptoms to CT examination was 3.6 d (range 1-9 d) in the seven COVID-19 patients. The lesions were distributed in single lung in one case and bilateral lungs in six cases. The lesions involved middle and lateral fields of lungs in five cases and the whole field of lungs in two cases. The lesions showed ground-glass opacity in four cases and mixed shadow in three cases. The lesions involved two or less lobes in four cases and five lobes in three cases. One case had air bronchogram. No mediastinal lymphadenopathy or pleural effusion were found. Conclusion COVID-19 patients have characteristic CT findings, which has important clinical significance for the diagnosis and treatment of COVID-19. However, the diagnosis should be confirmed based on the patient's epidemic history, clinical symptoms and laboratory indicators.

An acceptable method to evaluate the analytical performance of real-time fluorescent RT-PCR targeting SARS-CoV-2 (preprint)

It was necessary to carry out methodologies evaluations of real-time fluorescent reverse-transcription PCR (RT-PCR) targeting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Considering biosafety issues and lack of positive specimens in some special locations in China, the routine specimens from healthy individuals were used to perform methodologies evaluations, in which the indexes were the differences of quantification cycle values ({Delta}Cq) between human derived internal reference control (IRC) genes of a specimen and quality control (QC). Serial experiments were carried out to evaluate various factors that might affect aforementioned methodologies, such as types of virus transport mediums, methods of specimen pretreatment and template preparation, specimen vortex strength, specimen storage temperature and duration. The results showed that using {Delta}Cq values as indexes, among various factors that might affect analytical performance, it was better to store specimens in the normal saline transport mediums, inactivate pathogens using water or metal bath, release more virus particles from swabs by vortex mixing, extract nucleic acids with centrifuge methods, and perform amplification assays timely. Aforementioned opinions and optimum conditions were further confirmed by SRAS-CoV-2 pseudovirus and clinical positive specimens. Altogether, the results of this study indicated that the routine specimens from healthy individuals could be used to evaluate the analytical performance of real-time fluorescent RT-PCR targeting SRAS-CoV-2, of which the indexes were the {Delta}Cq values between IRC genes of a specimen and QC. This acceptable method was extremely valuable in both theoretical and practical significance under current pandemic of coronavirus disease 2019 (COVID-19).