Unvaccinated Children Are an Important Link in the Transmission of SARS-CoV-2 Delta Variant (B1.617.2): Comparative Clinical Evidence From a Recent Community Surge.

Objective: To evaluate the necessity of Covid-19 vaccination in children aged < 12 y by comparing the clinical characteristics between unvaccinated children aged < 12 y and vaccinated patients aged ≥ 12y during the Delta surge (B.1.617.2) in Putian, Fujian, China. Methods: A total of 226 patients with SARS-Cov-2 Delta variant (B.1.167.2; confirmed by Real-time PCR positivity and sequencing) were enrolled from Sep 10th to Oct 20th, 2021, including 77 unvaccinated children (aged < 12y) and 149 people aged ≥ 12y, mostly vaccinated. The transmission route was explored and the clinical data of two groups were compared; The effect factors for the time of the nucleic acid negativization (NAN) were examined by R statistical analysis. Results: The Delta surge in Putian spread from children in schools to factories, mostly through family contact. Compared with those aged ≥ 12y, patients aged < 12y accounted for 34.07% of the total and showed milder fever, less cough and fatigue; they reported higher peripheral blood lymphocyte counts [1.84 (1.32, 2.71)×10^9/L vs. 1.31 (0.94, 1.85)×10^9/L; p<0.05), higher normal CRP rate (92.21% vs. 57.72%), lower IL-6 levels [5.28 (3.31, 8.13) vs. 9.10 (4.37, 15.14); p<0.05]. Upon admission, their COVID19 antibodies (IgM and IgG) and IgG in convalescence were lower [0.13 (0.00, 0.09) vs. 0.12 (0.03, 0.41), p<0.05; 0.02 (0.00, 0.14) vs. 1.94 (0.54, 6.40), p<0.05; 5.46 (2.41, 9.26) vs. 73.63 (54.63, 86.55), p<0.05, respectively], but longer NAN time (18 days vs. 16 days, p=0.13). Conclusion: Unvaccinated children may be an important link in the transmission of SARS-CoV-2 delta variant (B1.617.2), which indicated an urgent need of vaccination for this particular population.

Unvaccinated Children Are an Important Link in the Transmission of SARS-CoV-2 Delta Variant (B1.617.2): Comparative Clinical Evidence From a Recent Community Surge

Objective To evaluate the necessity of Covid-19 vaccination in children aged < 12 y by comparing the clinical characteristics between unvaccinated children aged < 12 y and vaccinated patients aged ≥ 12y during the Delta surge (B.1.617.2) in Putian, Fujian, China. Methods A total of 226 patients with SARS-Cov-2 Delta variant (B.1.167.2;confirmed by Real-time PCR positivity and sequencing) were enrolled from Sep 10th to Oct 20th, 2021, including 77 unvaccinated children (aged < 12y) and 149 people aged ≥ 12y, mostly vaccinated. The transmission route was explored and the clinical data of two groups were compared;The effect factors for the time of the nucleic acid negativization (NAN) were examined by R statistical analysis. Results The Delta surge in Putian spread from children in schools to factories, mostly through family contact. Compared with those aged ≥ 12y, patients aged < 12y accounted for 34.07% of the total and showed milder fever, less cough and fatigue;they reported higher peripheral blood lymphocyte counts [1.84 (1.32, 2.71)×10

Herd immunity theory and the control of COVID-19

The novel coronavirus infection was detected in the world at the end of December 2019. The pneumonia caused by novel coronavirus infection is named "COVID-19". Novel coronavirus has different coping strategies from various countries such as China and the UK, from the early diagnosis of "unknown pneumonia" to the continuous spread of the epidemic and the rapid growth of pneumonia cases. Is Britain's "herd immunity" strategy working? To focus on the second question, this study attempts to discuss and illustrate the effectiveness and feasibility of the "herd immunity" strategy in the management and control of COVID-19 by introducing the principles and methods of herd immunity, as well as previous cases, in combination with the theoretical model applied to COVID-19. The results showed that the "herd immunity" strategy is difficult to implement in the process of containing the spread of COVID-19. This study provided a reference for the prevention research of other infectious diseases.

Correlation between chest CT severity score and laboratory indicators in patients with Coronavirus disease 2019 (COVID-19).

OBJECTIVE: The association between computed tomography (CT) and clinical severity of COVID-19 has been demonstrated. However, there are few studies on CT and laboratory indicators in patients in COVID-19. Our aim was to explore the correlation between chest CT images and laboratory indicators of patients with COVID-19 pneumonia. METHODS: This was a retrospective study of patients with COVID-19 diagnosed and treated at the Affiliated Hospital of Putian University from 24 January 2020 to 6 March 2020. The correlation test between first chest CT score and blood cell analysis, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), blood biochemistry and T lymphocyte subsets (T-Ls) was investigated. RESULTS: Among the 56 patients, there were 36 (64.3%) males and 20 (35.7%) females. The mean age of the patients was 46.54 ± 15.82 (range, 15-86) years. The CT score in the moderate group was higher than in the mild group (5.06 ± 0.77 vs 1.87 ± 0.88, P < .05), and higher in the severe group than in the moderate and mild groups (10.71 ± 4.21, P < .05). In addition, the ESR was significantly higher in the severe group than mild group (32.00 (26.04, 58.24) vs 11.00 (7.84, 24.70) mm/h, P < .05). The CD3, CD4, CD8 and CD4/CD8 cells were not different (all P > .05). The CT scores of all patients correlated positively with CRP, LDH and ESR (all P < .01). CONCLUSION: The chest CT characteristics of patients with COVID-19 correlated positively with CRP, ESR and LDH, which may use one of the indicators for the assessment of disease severity.

The value of repeated CT in monitoring the disease progression in moderate COVID-19 pneumonia: A single-center, retrospective study.

ABSTRACT: The role of thoracic CT (computerized tomography) in monitoring disease course of COVID-19 is controversial. The purpose of this study is to investigate the risk factors and predictive value of deterioration on repeatedly performed CT scan during hospitalization.All COVID-19 patients treated in our isolation ward, from January 22, 2020 to February 7, 2020, were reviewed. Patients included were categorized into RD (Radiological Deterioration) group or NRD (No Radiological Deterioration) group according to the manifestation on the CT routinely performed during the hospitalization. All clinical data and CT images were analyzed.Forty three patients were included in our study. All are moderate cases with at least 4 CT scans each. Eighteen (42.9%) patients had radiological deteriorations which were all identified in CT2 (the first CT after admission). Patients in RD group had lower leukocyte count (P = .003), lymphocyte count (P = .030), and higher prevalence (P = .012) of elevated C-reactive protein (CRP) at admission. NRD patients had a lower prevalence of reticulations (P = .034) on baseline CT (CT1, performed within 2 days before admission) and a longer duration between symptom onset and the time of CT2 (P < .01). There was no significant difference in hospital stay or fibrotic change on CT4 (follow-up CT scan performed 4 weeks after discharge) between 2 groups. Shorter duration between symptom onset and CT2 time (odds ratio [OR], 0.436; 95% confidence interval: 0.233-0.816; P < .01) and lower leukocyte count in baseline evaluation (OR, 0.316; 95% CI: 0.116-0.859; P < .05) were associated with increased odds of radiological deterioration on CT image during hospitalization.For moderate COVID-19 patients, the value of routinely performed CT during the treatment is limited. We recommend avoiding using CT as a routine monitor in moderate COVID-19 patients.

Clinical characteristics of 199 discharged patients with COVID-19 in Fujian Province: A multicenter retrospective study between January 22nd and February 27th, 2020.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has quickly spread throughout the country and the world since first broke out in Wuhan, China. The outbreak that started from January 22, 2020, in Fujian Province has been controlled as the number of indigenous cases has not increased since March. We aimed to describe the clinical characteristics of patients with COVID-19 in Fujian Province, China. METHODS: In this retrospective, multicenter study, we collected and analyzed the epidemiological, clinical, and laboratory data of all cases confirmed by nucleic acid tests in five designated hospitals in Fujian Province between January 22 and February 27, 2020. All patients were followed up until discharge. COVID-19 severity was classified as mild, moderate, severe, or critical. RESULTS: Of 199 discharged patients with COVID-19, 105 patients were male, with a median age of 46.3 years, and 17 patients were severe, and 5 patients were critical on admission. Hypertension and diabetes were the most common comorbidities. The symptoms at illness onset were mainly fever (76.4%), cough (60.8%), and myalgia or fatigue (27.6%). A total of 96.5% of patients had abnormal imaging findings on chest computed tomography. Lymphopenia (37.2%) and hypoxemia (13.6%) were observed. Acute respiratory distress syndrome and respiratory failure occurred in 9 patients (4.5%) and 8 patients (4.0%) respectively. One patient died and the others were cured and discharged with the median hospital stay of 19 days. Old age was negatively correlated with lymphocyte count (r = - 0.296, p < 0.001) and oxygenation index (r = - 0.263, p = 0.001). Bivariate regression analysis revealed that old age (≥ 75 years), hypertension, diabetes, and lymphopenia were correlated with the severity of COVID-19. CONCLUSIONS: Patients in Fujian Province were mostly nonsevere cases with mild or moderate symptoms, and had a lower mortality than patients in Wuhan (4.3%-15%). Older age, hypertension, diabetes, and lymphopenia were risk factors for severity of COVID-19.

Dysfunction of adaptive immunity is related to severity of COVID-19: a retrospective study.

BACKGROUND: In December of 2019, coronavirus disease 2019 (Covid-19) was reported in Wuhan, China, and has now rapidly swept around the world. Much research has been carried out since the outbreak, but few studies have focused on the dysfunction of the adaptive immunity. METHODS: In this retrospective and multi-center study, 373 patients with laboratory-confirmed COVID-19 from Shanghai Public Health Clinical Center and Affiliated Hospital of Putian University were recruited. Demographic, clinical, radiological features, and laboratory data were recorded and analyzed at admission and at discharge. Results of immunological tests were followed up until the patients were discharged. RESULTS: Of the 373 patients with COVID-19 pneumonia, 322 were in the non-severe group and 51 were in the severe group. Number of T cells, CD4+ and CD8+ T cells, and total lymphocytes declined remarkably upon admission and elevated when the patients were discharged. At admission, counts of total lymphocytes, T cells, CD4+ and CD8+ T cells, and levels of C3 and C4 in the severe group were lower than those in the non-severe group, whereas the neutrophil to lymphocyte ratio (NLR) was higher in the severe group. Counts of T cells, CD4+ and CD8+ T cells, and total lymphocytes were negatively correlated with lactate dehydrogenase and C-reactive protein. CONCLUSION: COVID-19 might target adaptive immunity and cause a decrease in lymphocytes, especially T cells and subsets. Physicians should pay close attention to the adaptive immunity of patients upon admission. Monitoring NLR, T lymphocytes, and subsets would help physicians with the proper diagnosis and treatment of COVID-19.The reviews of this paper are available via the supplemental material section.