[Effects of vaccines on the viral negative conversion of children with COVID-19].

Objective: To explore the effect of vaccination on viral negative conversion of children with COVID-19. Methods: A retrospective cohort study was conducted. A cohort of 189 children aged 3-14 years with COVID-19 admitted to Renji Hospital (South branch) of Shanghai Jiao Tong University School of Medicine from April 7th to May 19th 2022 was enrolled in the study. According to the vaccination status, the infected children were divided into an unvaccinated group and a vaccinated group. Age, gender, severity, clinical manifestations, and laboratory tests, etc. were compared between groups, by rank sum test or chi-square test. The effects of vaccination on viral negative conversion were analyzed by a Cox mixed-effects regression model. Additionally, a questionnaire survey was conducted among the parents of unvaccinated children to analyze the reasons for not being vaccinated. Results: A total of 189 children aged 3-14 years were enrolled, including 95 males (50.3%) and 94 females (49.7%), aged 5.7 (4.1,8.6) years. There were 117 cases (61.9%) in the unvaccinated group and 72 cases (38.1%) in the vaccinated group. The age of the vaccinated group was higher than that of the unvaccinated group (8.8 (6.8, 10.6) vs. 4.5 (3.6, 5.9) years, Z=9.45, P<0.001). No significant differences were found in clinical manifestations, disease severity, and laboratory results between groups (all P>0.05), except for the occurrence rate of cough symptoms, which was significantly higher in the vaccinated group than in the non-vaccinated group (68.1% (49/72) vs. 50.4% (59/117),χ2=5.67, P=0.017). The Kaplan-Meier survival curve and Cox mixed-effects regression model showed that the time to the viral negative conversion was significantly shorter in the vaccinated group compared with the unvaccinated group (8 (7, 10) vs. 11 (9, 12) d, Z=5.20, P<0.001; adjusted HR=2.19 (95%CI 1.62-2.97)). For questionnaire survey on the reasons for not receiving a vaccination, 115 questionnaires were distributed and 112 valid questionnaires (97.4%) were collected. The main reasons for not being vaccinated were that parents thought that their children were not in the range of appropriate age for vaccination (51 cases, 45.5%) and children were in special physical conditions (47 cases, 42.0%). Conclusion: Vaccination can effectively shorten the negative conversion time of children with COVID-19 and targeted programs should be developed to increase eligible children's vaccination rate for SARS-CoV-2 vaccination.

Direct visualization of single-cell non-repetitive genes by in situ activation of collateral activity of CRISPR/Cas12a inside cells

The spread of drug-resistance bacteria is a serious issue of environment. Tools allowing to image single-cell genes can provide key information about the spatial pattern and heterogeneity of cell population. Herein, we explored the possibility of in situ activation of collateral trans-cleavage activity of CRISPR/Cas12a inside cells, to achieve a direct detection of single-cell non-repetitive genes. CRISPR/Cas12a allows to recognize target genes without the need for denaturation or digestion process. Particularly, the target gene-activated trans-cleavage by CRISPR/ Cas12a inside cells outputs an amplified signal for the gene recognition, allowing to visualize non-repetitive genes. The signal-to-background ratio for imaging drug-resistance gene, oqxB in the Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) was further improved by combining multiple binding of Cas12a, enabled imaging of drug-resistance S. Typhimurium isolated from poultry farm and in the intestinal tract sec-tions. Single-cell investigation of S. Typhimurium under salt stress indicated that drug-sensitive strain owned a survival advantage over drug-resistance strain at high-content salt environment. This gene imaging methods holds potential for detecting the spread of drug resistance in the environment and serves as a means to inves-tigate the relationship between genotype and phenotype at single-cell level.

Perinatal and neonatal management plan for prevention and control of SARS-CoV-2 infection (2nd Edition)

Since late December 2019, SARS-CoV-2 infection has spread to all parts of the country and overseas, and the outbreak continues. At the end of January 2020, the Working Group for the Prevention and Control of Neonatal SARSCoV-2 Infection in the Perinatal Period of the Editorial Committee of Chinese Journal of Contemporary Pediatrics worked out the perinatal and neonatal management plan for prevention and control of SARS-CoV-2 infection (1st Edition). This plan has been verified by clinical practice for 3 weeks. With the further understanding of SARS-CoV-2 infection, especially the emergence of SARS-CoV-2 infection cases in pregnant women and neonates, it is necessary to update the first edition of the management plan so as to offer a better guide on clinical practice. Therefore, the Working Group has worked out the second edition of the management plan.

[Influence of coronavirus disease 2019 on the nervous system of children]

Coronavirus disease 2019 (COVID-19) has become a worldwide pandemic and can occur at any age, including children. Children with COVID-19 can develop the clinical symptoms of multiple systems, among which symptoms of the nervous system have been reported increasingly, and thus it is particularly important to understand COVID-19-associated neurological damage in children. This article reviews the mechanisms and types of COVID-19-associated neurological damage in children.