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Preprint in English | medRxiv | ID: ppmedrxiv-21266499


ObjectivesAs the COVID-19 pandemic is still ongoing and SARS-CoV-2 variants are circulating worldwide, an increasing number of breakthrough infections have been detected despite the good efficacy of COVID-19 vaccines. MethodsA prospective, comparative cohort study was conducted in Beijing Ditan Hospital to evaluate the clinical, immunological and genomic characteristics of COVID-19 breakthrough infections. Data on 88 COVID-19 breakthrough cases (vaccinated group) and 41 unvaccinated cases (unvaccinated group) from June 1 to August 20, 2021 were extracted from a cloud database. Among these 129 COVID-19 cases, we successfully sequenced 33 whole genomes, including 16 from the vaccinated group and 17 from the unvaccinated group. ResultsAsymptomatic and mild cases predominated in both groups, but 2 patients developed severe disease in the unvaccinated group. Between the two groups, the median time of viral shedding in the vaccinated group were significantly lower than those in the unvaccinated group (p = 0.003). A comparison of dynamic IgG titres of cases in the two groups indicated that IgG titres in the vaccinated group showed a significantly increasing trend (P =0.028). The CD4+T lymphocyte count was lower in the unvaccinated group, and there was a significant difference between the two groups (p=0.018). In the vaccinated group, the number of moderate cases who received Sinopharm BBIBP (42 cases) was significantly higher than those who received Sinovac Coronavac (p=0.020). Whole-genome sequencing revealed 23 cases of delta variants, including 15 patients from the vaccinated group. However, no significant difference was observed in either the RT-qPCR results or viral shedding time. ConclusionsCOVID-19 vaccine breakthrough infections were mainly asymptomatic and mild, the IgG titres were significantly higher and increased rapidly, and the viral shedding was short. Delta variants may be more likely to cause breakthrough infections, and vaccination may not reduce the viral loads and shedding time.

Preprint in English | medRxiv | ID: ppmedrxiv-21256655


BackgroundThe SARS-CoV-2 B.1.1.7 variant which was first identified in the United Kingdom (U.K.) has increased sharply in numbers worldwide and was reported to be more contagious. On January 17, 2021, a COVID-19 clustered outbreak caused by B.1.1.7 variant occurred in a community in Daxing District, Beijing, China. Three weeks prior, another non-variant (lineage B.1.470) COVID-19 outbreak occurred in Shunyi District, Beijing. This study aimed to investigate the clinical features of B.1.1.7 variant infection. MethodsA prospective cohort study was conducted on COVID-19 cases admitted to Ditan hospital since January 2020. Data of 74 COVID-19 cases from two independent COVID-19 outbreaks in Beijing were extracted as study subjects from a Cloud Database established in Ditan hospital, which included 41 Shunyi cases (Shunyi B.1.470 group) and 33 Daxing cases (Daxing B.1.1.7 group) that have been hospitalized since December 25, 2020 and January 17, 2021, respectively. We conducted a comparison of the clinical characteristics, RT-qPCR results and genomic features between the two groups. FindingsCases from Daxing B.1.1.7 group (15 [45.5%] male; median age, 39 years [range, 30.5, 62.5]) and cases from Shunyi B.1.470 group (25 [61.0%] male; median age, 31 years [range, 27.5, 41.0]) had a statistically significant difference in median age (P =0.014). Seven clinical indicators of Daxing B.1.1.7 group were significantly higher than Shunyi B.1.470 group including patients having fever over 38{degrees}C (14/33 [46.43%] in Daxing B.1.1.7 group vs. 9/41 (21.95%) in Shunyi B.1.470 group [P = 0 .015]), C-reactive protein ([CRP, mg/L], 4.30 [2.45, 12.1] vs. 1.80, [0.85, 4.95], [P = 0.005]), Serum amyloid A ([SAA, mg/L], 21.50 [12.50, 50.70] vs. 12.00 [5.20, 26.95], [P = 0.003]), Creatine Kinase ([CK, U/L]), 110.50 [53.15,152.40] vs. 70.40 [54.35,103.05], [P = 0.040]), D-dimer ([DD, mg/L], 0.31 [0.20, 0.48] vs. 0.24 [0.17,0.31], [P = 0.038]), CD4+ T lymphocyte ([CD4+ T, mg/L], [P = 0.003]), and Ground-glass opacity (GGO) in lung (15/33 [45.45%] vs. 5/41 [12.20%], [P =0.001]). After adjusting for the age factor, B.1.1.7 variant infection was the risk factor for CRP (P = 0.045, Odds ratio [OR] 2.791, CI [1.025, 0.8610]), SAA (0.011, 5.031, [1.459, 17.354]), CK (0.034, 4.34, [0.05, 0.91]), CD4+ T (0.029, 3.31, [1.13, 9.71]), and GGO (0.005, 5.418, [1.656, 17.729]) of patients. The median Ct value of RT-qPCR tests of the N-gene target in the Daxing B.1.1.7 group was significantly lower than the Shunyi B.1.470 group (P=0.036). The phylogenetic analysis showed that only 2 amino acid mutations in spike protein were detected in B.1.470 strains while B.1.1.7 strains had 3 deletions and 7 mutations. InterpretationClinical features including a more serious inflammatory response, pneumonia and a possible higher viral load were detected in the cases infected with B.1.1.7 SARS-CoV-2 variant. It could therefore be inferred that the B.1.1.7 variant may have increased pathogenicity. FundingThe study was funded by the National Key Research and Development Program (grant nos.2020YFC0846200 and 2020YFC0848300) and National Natural Science Foundation of China (grant no. 82072295).

Preprint in English | medRxiv | ID: ppmedrxiv-20175455


BackgroundBoth COVID-19 and influenza A contribute to increased mortality among the elderly and those with existing comorbidities. Changes in the underlying immune mechanisms determine patient prognosis. This study aimed to analyze the role of lymphocyte subsets in the immunopathogenesisof COVID-19 and severe influenza A, and examined the clinical significance of their alterations in the prognosis and recovery duration. MethodsBy retrospectively reviewing of patients in four groups (healthy controls, severe influenza A, non-severe COVID-19 and severe COVID-19) who were admitted to Ditan hospital between 2018 to 2020, we performed flow cytometric analysis and compared the absolute counts of leukocytes, lymphocytes, and lymphocyte subsets of the patients at different time points (weeks 1- 4). ResultsWe reviewed the patients data of 110 healthy blood donors, 80 Non-severe-COVID-19, 19 Severe-COVID-19 and 43 severe influenza A. We found total lymphocytes (0.93 x109/L, 0.84 x109/L vs 1.78 x109/L, P < 0.0001) and lymphocyte subsets (T cells, CD4+ and CD8+ T cell subsets) of both severe patients to be significantly lower than those of healthy donors at early infection stages. Further, significant dynamic variations were observed at different time points (weeks 1-4). ConclusionsOur study indicates lymphopenia to be associated with disease severity and suggests the plausible role of lymphocyte subsets in disease progression, which in turn affects prognosis and recovery duration in patients with severe COVID-19 and influenza A.

Preprint in English | medRxiv | ID: ppmedrxiv-20021584


BackgroundSevere ill patients with 2019 novel coronavirus (2019-nCoV) infection progressed rapidly to acute respiratory failure. We aimed to select the most useful prognostic factor for severe illness incidence. MethodsThe study prospectively included 61 patients with 2019-nCoV infection treated at Beijing Ditan Hospital from January 13, 2020 to January 31, 2020. Prognostic factor of severe illness was selected by the LASSO COX regression analyses, to predict the severe illness probability of 2019-CoV pneumonia. The predictive accuracy was evaluated by concordance index, calibration curve, decision curve and clinical impact curve. ResultsThe neutrophil-to-lymphocyte ratio (NLR) was identified as the independent risk factor for severe illness in patients with 2019-nCoV infection. The NLR had a c-index of 0.807 (95% confidence interval, 0.676-0.38), the calibration curves fitted well, and the decision curve and clinical impact curve showed that the NLR had superior standardized net benefit. In addition, the incidence of severe illness was 9.1% in age [≥] 50 and NLR < 3.13 patients, and half of patients with age [≥] 50 and NLR [≥] 3.13 would develop severe illness. Based on the risk stratification of NLR with age, the study developed a 2019-nCoV pneumonia management process. ConclusionsThe NLR was the early identification of risk factors for 2019-nCoV severe illness. Patients with age [≥] 50 and NLR [≥] 3.13 facilitated severe illness, and they should rapidly access to intensive care unit if necessary.