ABSTRACT
Objectives: As 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. Methods: A 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. Results: Asymptomatic 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. Conclusions: COVID-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.
Subject(s)
COVID-19 , Breakthrough PainABSTRACT
Background: The 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. Methods: A 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. Findings: Cases 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 (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. Interpretation: Clinical 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.
Subject(s)
Fever , Pneumonia , COVID-19ABSTRACT
Background Towards the end of December 2019, the Wuhan health commission declared an outbreak of clusters of pneumonia in patients. Sequencing indicated that this disease (COVID-19) was caused by a novel coronavirus (SARS-CoV-2). The outbreak of COVID-19 is currently still underway.Methods We recruited 75 SARS-CoV-2 infected patients admitted to the Center of Infectious Disease division 2 of Beijing Ditan Hospital from Jan 20 to Mar 20, 2020. Epidemiological, demographic, clinical, radiological features, laboratory data were analyzed.Results Of the 75 patients, 42(56%) patients were male and 33(44%) patients were female. The mean age of all patients was 41.5 ± 19.4 years. Male patients were more likely to become severe. There were 9 family clusters accounted for 44 patients. Patients classified as being severe had a higher frequency of fever upon admission than patients classified as moderate cases. For moderate patients, the median duration of viral shedding was 25(9.5, 42) days (range 1–63 days) from the first positive nucleic acid test compared to 14(9, 21.25) days (range 2–62 days) for severe cases. The difference between the two groups was statistically significant (p = 0.041). Cox regression analyses indicated that disease status and CRP were the factors that affect the duration of viral shedding. Virus clearance was significantly faster in severe patients compared to moderate patients(p = 0.011), and patients with CRP range in 2–10 times higher than upper limit of normal value had longer duration of viral shedding(p = 0.012). CRP and CD4 + T lymphocyte was negative correlated, and the relationship between CRP and CD4 + T lymphocyte was statistically significant (P = 0.003), with a correlation coefficient of -0.564. During the second week following the onset of illness, severe cases had higher WBC, NEU and CRP, but lower LYM, MON and EOS as compared with moderate cases (all P < 0.05). Severe cases still had lower lymphocyte counts and higher CRP than moderate cases in the third week.Conclusions Viral clearance was significantly prolonged in moderate patients, and those CRP in 2–10 times higher than upper limit of normal value. Immune response may affect the duration of viral shedding. Severe cases had a persistence lower lymphocyte count and higher CRP than moderate cases.