Clinical follow-up study of SARS-CoV-2 Omicron infection / 上海预防医学

ObjectiveTo observe the clinical course and explore the risk factors for SARS-CoV-2 RNA negative conversion duration （NCD） in asymptomatic and mild-symptomatic patients infected with the SARS-CoV-2 Omicron variant. MethodsClinical data were collected from 244 confirmed cases of corona virus disease （COVID-19） with Omicron variant infection admitted to a temporal makeshift hospital in Shanghai from April 9， 2022 to May 20， 2022. Demographic and clinical data were analyzed， with a primary focus on the time of COVID-19 nucleic acid conversion. Univariate and multivariate Cox regression analysis were used to determine identify risk factors associated with NCD. ResultsThe median duration of negative RNA conversion was 9 days （ranged 7‒12 days）. The percentage of patients with positive nucleic acid results on the 5th， 7th， 10th， and 14th days after confirmed infection was 68.4%， 47.1%， 20.1%， and 5.7%， respectively. Kaplan-Meier curves indicated a median nucleic acid conversion time of 12 days （ranged 10‒14 days） for patients with hypertension， 9 days （ranged 7‒11 days） in patients without hypertension， and 11 days （ranged 9‒13 days） for patients aged ≥60 years， and 9 days （ranged 7‒11 days） for patients aged <60 years. Multivariate Cox regression analysis showed that only hypertension was an independent risk factor of NCD （RR=1.60； 95% CI： 1.03‒2.49， P=0.036）. ConclusionIn asymptomatic or mildly symptomatic patients infected with the Omicron variant， 20.1% patients continue to exhibit positive viral nucleic acid on the 10th days of infection. The independent risk factor associated with the conversion of SARS-CoV-2 nucleic acid to negative is hypertension.

Comparative analysis of asymptomatic infection prevalence in Beta, Delta, and Omicron surges of COVID-19

Abstract Background The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has had a devastating impact on the global population, with an estimated 650 million people infected and more than 6.6 million lives lost. Asymptomatic individuals have been shown to play a significant role in the transmission of the virus. Therefore, this study aims to investigate and compare the prevalence of asymptomatic individuals across three waves associated with the Beta, Delta, and Omicron variants of the virus. Methods This retrospective study was conducted between December 2020 and March 2022. The study population consisted of passengers on international flights who were referred to the Gerash Clinical and Molecular Diagnosis Laboratory. Real-time PCR was employed for the diagnosis of SARS-CoV-2. Results Out of a total of 8592 foreign travelers referred to our laboratory, 139 (1.16 %) tested positive for SARS-CoV-2 infection and were asymptomatic. During the Beta surge, 35 (1.49 %) out of 2335 passengers tested positive for SARS-CoV-2. In the Delta surge, 31 (0.6 %) out of 5127 passengers tested positive. However, during the Omicron surge, a significantly higher number of passengers, specifically 73 (6.46 %) out of 1130, had a positive result for the SARS-CoV-2 test. Conclusion Considering the significant role of asymptomatic transmission in the spread of COVID-19, it is imperative to reconsider health policies when dealing with future surges of the Omicron subvariants. Additionally, we strongly recommend that the World Health Organization prioritize the development and distribution of second-generation vaccines that target not only disease but also infection prevention.

Trends of humoral immune responses to heterologous antigenic exposure due to vaccination & omicron SARS-CoV-2 infection: Implications for boosting

Background & objectives: Vaccination and natural infection can both augment the immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but how omicron infection has affected the vaccine-induced and hybrid immunity is not well studied in Indian population. The present study was aimed to assess the durability and change in responses of humoral immunity with age, prior natural infection, vaccine type and duration with a minimum gap of six months post-two doses with either ChAdOx1 nCov-19 or BBV152 prior- and post-emergence of the omicron variant. Methods: A total of 1300 participants were included in this observational study between November 2021 and May 2022. Participants had completed at least six months after vaccination (2 doses) with either ChAdOx1 nCoV-19 or an inactivated whole virus vaccine BBV152. They were grouped according to their age (? or ?60 yr) and prior exposure of SARS-CoV-2 infection. Five hundred and sixteen of these participants were followed up after emergence of the Omicron variant. The main outcome was durability and augmentation of the humoral immune response as determined by anti-receptor-binding domain (RBD) immunoglobulin G (IgG) concentrations, anti-nucleocapsid antibodies and anti-omicron RBD antibodies. Live virus neutralization assay was conducted for neutralizing antibodies against four variants – ancestral, delta and omicron and omicron sublineage BA.5. Results: Before the omicron surge, serum anti-RBD IgG antibodies were detected in 87 per cent participants after a median gap of eight months from the second vaccine dose, with a median titre of 114 [interquartile range (IQR) 32, 302] BAU/ml. The levels increased to 594 (252, 1230) BAU/ml post- omicron surge (P<0.001) with 97 per cent participants having detectable antibodies, although only 40 had symptomatic infection during the omicron surge irrespective of vaccine type and previous history of infection. Those with prior natural infection and vaccination had higher anti-RBD IgG titre at baseline, which increased further [352 (IQR 131, 869) to 816 (IQR 383, 2001) BAU/ml] (P<0.001). The antibody levels remained elevated after a mean time gap of 10 months, although there was a decline of 41 per cent. The geometric mean titre was 452.54, 172.80, 83.1 and 76.99 against the ancestral, delta, omicron and omicron BA.5 variants in the live virus neutralization assay. Interpretation & conclusions: Anti-RBD IgG antibodies were detected in 85 per cent of participants after a median gap of eight months following the second vaccine dose. Omicron infection probably resulted in a substantial proportion of asymptomatic infection in the first four months in our study population and boosted the vaccine-induced humoral immune response, which declined but still remained durable over 10 months

Scientometric Research Mapping of OMICRON for Scientific Production: A Global Perception Analysis

Background: South Africa reported a new variant of SARS-CoV-2, named 'Omicron,' to the World Health Or-ganization on November 24, 2021. Scientometric analysis quantify all currently available written communica-tion, the authors of that communication, and their citation analysis. The study's goal was to use the Scopus and Web of Science databases to look at the research metrics of Omicron publications published between Jan-uary 1965 and March 2020. Methods:All scientific research outputs with the word 'Omicron' in the title were retrieved from the Web of Science (January 1965 to March 2022) and Scopus (January 1896 to March 2022) databases on April 10, 2022. The data was analyzed based on year-wise publications; leading authors; predominant journals in publishing, highly cited articles with citations; type of publications; subject classification, frequently used keywords, geo-graphical distribution of publication, language, and more contributed institutions. Results: There were 1229 research outputs for WoS and 655 from Scopus. The number of publications for WoS increased from 22 in 1965 to 265 in 2022, while Scopus increased from 1 in 1896 to 356 in 2022. Both the databases identified the author Yuen KY as the highest contributor; Journal of Virology and Nature as the predominant journals; the Lancet as highly cited journal; majority as original articles; frequently used key-words as 'SARS-CoV-2'; the United States of America as the most productive country; majority publication in English. The publications were mainly on the subjects Chemistry and Medicine by WoS and Scopus, respec-tively. The most productive institute was the ‘University of California Systems’ by WoS and the ‘University of Hong Kong’ by Scopus. Conclusion: The term 'Omicron' first appeared in the domain of Chemistry in the late 18th century. The growth pattern of publication was not consistent. The above research metrics will be helpful to researchers in the coming days.

Variante mexicana de COVID-19: ómicron BW. 1 o Xibalbá / Mexican variant of COVID-19: omicron BW. 1 o Xibalbá

Introducción: desde la aparición del COVID-19 a principios de diciembre del año 2019, en la ciudad China de Wuhan, esta enfermedad respiratoria empezó a avanzar a nivel mundial. El 30 de enero de 2020, la Organización Mundial de la Salud declaró a esta enfermedad con carácter epidémico y como una situación de emergencia a nivel mundial. El propósito de este estudio es presentar información de la variante ómicron BW.1 o Xibalbá. Conclusión: México está en un proceso de transición de pandemia hacia endemia, pero no quiere decir que no seguirán apareciendo nuevas variantes como ocurrió en la quinta ola (ómicron BA.5) o con subvariantes que emergieron como BW.1 «Xibalbá¼, BQ.1 «perro del infierno¼ y XBB «pesadilla¼. La población y los gobiernos deberán continuar con las medidas preventivas establecidas desde el inicio de la pandemia como son el uso de cubrebocas, el correcto lavado de manos y de ropa, los hábitos de higiene, limpieza, desinfección personal y de nuestro entorno, el aislamiento precoz ante alguna sintomatología y la vacunación (ya sea la primera o sus refuerzos subsecuentes).(AU)

Introduction: since the appearance of COVID-19 in early December 2019 in the Chinese city of Wuhan, this respiratory disease began to spread worldwide. On the thirtieth of January of the year two thousand and twenty, the World Health Organization (WHO) declared this disease to be epidemic and with a worldwide emergency situation. The purpose of the study is to present information on the Omicron BW.1 or Xibalba variant. Conclusion: Mexico is in a process of transition from pandemic to endemic but this does not mean that new variants will not continue to appear as they did in the fifth wave (omicron BA.5) or subvariants that emerged such as: BW.1 or «Xibalbá¼, BQ.1 «hellhound¼ and XBB «nightmare¼. The population and governments should continue with the preventive measures established since the beginning of the pandemic, such as: use of masks, proper hand and clothing washing, hygiene habits, personal and environmental cleaning and disinfection, early isolation in case of any symptomatology, and vaccination, either first or subsequent boosters.(AU)

Clinical characteristics and prognosis in 12 children with SARS-CoV-2 Omicron variant infection-associated acute necrotizing encephalopathy / 中国当代儿科杂志

OBJECTIVES@#To study the clinical characteristics and prognosis of SARS-CoV-2 Omicron variant infection-associated acute necrotizing encephalopathy (ANE) in children .@*METHODS@#A retrospective analysis was conducted on the medical data of 12 children with SARS-CoV-2 Omicron variant infection-associated ANE who were admitted to the Pediatric Intensive Care Unit, Qingdao Women and Children's Hospital from December 18 to 29, 2022. The children were divided into two groups based on outcomes: death group (7 cases) and survival group (5 cases). The clinical manifestations and auxiliary examination results were compared between the two groups.@*RESULTS@#The median age of the 12 patients was 30 months, with a male-to-female ratio of 1:1. All patients presented with persistent high fever, with a median highest body temperature of 41℃. The median time from fever onset to seizure or consciousness disturbance was 18 hours. The death group had a higher proportion of neurogenic shock, coagulation dysfunction, as well as elevated lactate, D-dimer, interleukin-6, interleukin--8, and interleukin-10 levels compared to the survival group (P<0.05).@*CONCLUSIONS@#Children with SARS-CoV-2 Omicron variant infection-associated with ANE commonly present with persistent high fever, rapidly progressing disease, and have a high likelihood of developing consciousness disorders and multiorgan dysfunction within a short period. The occurrence of neurogenic shock, coagulation dysfunction, and significantly elevated cytokine levels suggests an increased risk of mortality.

Clinical characteristics of children with Omicron variant infection in Chengdu area, China / 中国当代儿科杂志

OBJECTIVES@#To investigate the clinical characteristics of children infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Chengdu of China.@*METHODS@#A retrospective analysis was conducted for the clinical data of 226 children who were infected with the Omicron variant of SARS-Cov-2 and were isolated and treated in Chengdu Shelter Hospital from August 28 to September 21, 2022. According to the presence or absence of clinical symptoms, they were divided into two groups: asymptomatic group and mild symptomatic group. The two groups were compared in terms of clinical characteristics, diagnosis and treatment, and prognosis.@*RESULTS@#Among the 226 children infected with the Omicron variant, 71 (31.4%) were asymptomatic and 155 (68.6%) had mild symptoms. Fever and cough were the most common clinical symptoms, with fever in 95 children (61.3%) and cough in 92 children (59.4%). Of all 226 children, 188 (83.2%) received coronavirus disease 2019 (COVID-19) vaccination. The time to nucleic acid clearance ranged from 6 to 26 days, with a nucleic acid clearance rate of 58.0% (131/226). There were no significant differences among different age groups in sex, early symptoms, clinical typing, nucleic acid re-positive rate, nucleic acid clearance rate, and length of hospital stay (P>0.05). There were no significant differences between the asymptomatic and mild symptomatic groups in age, sex, underlying diseases, COVID-19 vaccination, use of Lianhua Qingwen granules, nucleic acid clearance rate, nucleic acid re-positive rate, and length of hospital stay (P>0.05).@*CONCLUSIONS@#Children infected with the Omicron variant of SARS-Cov-2 in Chengdu generally have mild clinical symptoms, mainly upper respiratory tract infection, which has little threat to the health of children of different ages, and children tend to have a good overall prognosis.

Changes and distribution of antibodies in plasma before and after infection of SARS-CoV-2 Omicron strain / 中国输血杂志

【Objective】 To determine the best collection time period of plasma which can be used for human COVID-19 immunoglobulin for intravenous injection through SARS-CoV-2-IgG change and neutralizing antibody distribution against different virus strain in representative mixed plasma before and after Omicron strain infection by ELISA and pseudovirus neutralization test. 【Methods】 An ELISA method for quantitative detection of SARS-CoV-2-IgG was established and its linear range,accuracy and precision was verified. SARS-CoV-2-IgG potency was detected in 25 convalescent plasma which were collected 20-40 days after confirmed Omicron infection, two groups of mixed plasma samples WP1 and WP2 were prepared according to the SARS-CoV-2-IgG results, and pseudovirus neutralization experiments with different virus strain (prototype strain, BA. 1,BA.2, BA.4/5, BF.7, BQ.1.1) were carried out to determine the distribution of neutralizing antibodies against different virus strain. SARS-CoV-2-IgG potency of representative mixed plasma collected from 14 plasma stations subordinate to the company before and after Omicron strain infection was detected, including Omicron convalescent plasma (OP) collected from different plasma stations from December 2022 to May 2023 and normal pool plasma (VN) feed in March 2023 which collected from March 2022 to December 2022. According to the results, the difference and the change rule with time of SARS-CoV-2-IgG before and after Omicron strain infection were analyzed. 【Results】 The linearity of SARS-CoV-2-IgG ranged from 6.25 to 200 EIU/mL, the accuracy in-batch ranged from 81.793% to 106.985%, the precision in-batch ranged from 1. 100% to 13.000%, and the total error in-batch ranged from 2.988% to 22.679%. The accuracy between batches ranged from 90.788%to 96.893%, the precision between batches ranged from 4.870% to 6.272%, and the total error between batches ranged from 9.192% to 15.399%. The results of pseudovirus neutralizing antibody showed that the potency of different virus strain neutralizing antibodies were in the order of prototype strain>BA.2>BA.4/5>BF.7≈ BQ.1.1>BA.1 and the correlation between WP1 and WP2 was high (Pearson r=0. 931 1, P=0.002 3) which indicated that the potency distribution of neutralizing antibodies of different virus strain in Omicron convalescent plasma was basically stable. Compared with the mixed convalescent plasma sample G128 collected in June 2022, the potency of Omicron neutralizing antibodies of WP series were significantly higher, the ratio of BA.2 antibody to prototype antibody increased from 26.9% (before infection) to 82.6%-87.5% (after infection). The results of VN series before Omicron infection were < 100 EIU/mL, and the results of OP series after Omicron infection showed that the plasma collected from the beginning of December 2022 was the peak of antibody in the same month,and then dropped sharply, entering a short plateau in February-March 2023 (potency was about 40% of the peak value),and then dropped sharply again in April (potency was about 20% of the peak value). 【Conclusion】 The potency and proportion of neutralizing antibody against Omicron subtype in convalescent plasma after COVID-19 Omicron strain infection increased significantly. IgG antibody of plasma donors in different regions reached its peak in the month of infection, then continued to dropped sharply. The best collection period of plasma that can be used for human COVID-19 immunoglobulin for intravenous injection was 1 to 2 months after infection.

Epidemiological investigation of a school COVID-19 outbreak in Shanghai / 上海预防医学

ObjectiveTo describe a COVID-19 outbreak due to SARS-CoV-2 Omicron variant in a school and provide suggestions for COVID-19 prevention and control. MethodsData on the COVID-19 outbreak in a school in Putuo District of Shanghai were collected from November 14 to December 20， 2022. Epidemiological characteristics， incidence rate of secondary cases and response measures were described and analyzed. ResultsA total of 27 COVID-19 cases were identified infected with SARS-CoV-2 Omicron BA.5.2 variant， including 14 students （51.9%） and 13 family members / teachers living with those students （48.1%）. The first case occurred on November 14， with peak incidence during November 16-18. The median generation interval of the second generation cases was 2 （2，3） days. The index case （case 1， a student） had a clear contact history outside the school， which was found through routine examination in key populations in the school. Immediate management was conducted after the notification. All the second generation cases were exposed students in the same class with case 1， which were identified during the quarantine， whereas the third generation cases were their family members/teachers living with the second generation cases. The incidence rate within the class and school were 36.8% and 3.0%， respectively. No further social transmission was found outside the school. ConclusionEarly detection， multi-sectoral collaboration， prompt control and quarantine measures are effective in containing SARS-CoV-2 transmission. Health promotion， surveillance， ventilation and prophylactic disinfection should be reinforced in schools， office buildings and other gathering places.

Epidemiological characterization of a cluster of COVID-19 caused by SARS-CoV-2 Omicron variant at a construction site in Qingpu District， Shanghai / 上海预防医学

ObjectiveTo determine the epidemiological characteristics of a cluster of SARS-CoV-2 Omicron variant at a construction site and provide evidence for further COVID-19 prevention and control. MethodsDemographic data of all COVID-19 cases at a construction site in Qingpu District， Shanghai， and basic information of the construction site were retrospectively collected through filed investigation. Descriptive epidemiology was used for the analysis. Basic reproduction number （R0） and time-dependent reproduction number （Rt） were calculated using R program. ResultsDuring April 12 and May 8， 2022， a total of 314 cases were reported at the construction site， with an attack rate of 60.62%. The attack rate significantly differed between workers and managers （χ2=10.868， P<0.001）， whereas did not differ statistically by gender （χ2=0.358， P=0.550） or by vaccination status （χ2=2.861， P=0.091）. The age of all cases ranged from 5 months of age to 68 years， with a media age of 49.0 years （interquartile range： 39.8， 54.0）. In all cases， male was predominant （83.44%）. Moreover， the epidemic was mainly concentrated in the workers’ dormitory area， with infected cases identified in all buildings of each dormitory area. The attack rate ranged between 33.33% and 87.50% across the buildings. Symptoms and signs were observed among 43.0% of all cases， of which major clinical manifestations included cough （33.33%）， fever （30.37%） and headache （17.04%）. Clinical manifestations did not differ by gender （χ2=1.275， P=0.259） or by vaccination status （χ2=0.186， P=0.666）. Additionally， R0 was estimated to be 6.08 （95% confidence interval： 4.49‒8.02）. The Rt showed a decline in the beginning， followed by an increase and a re-decline. ConclusionThe cluster epidemic of COVID-19 caused by Omicron variant at the construction site is highly contagious， spreads rapidly and quietly， causes mild symptoms， which finally resulted in a large number of infected cases. It warrants rapid and strict containment when an epidemic occurs at construction sites.

Spatiotemporal characteristics and prevention and control measures of SARS-CoV-2 Omicron pandemic in Shanghai / 上海预防医学

ObjectiveTo analyze the spatiotemporal characteristics and prevention and control measures of the pandemic caused by the SARS-CoV-2 Omicron variant in Shanghai in 2022， aiming to optimize future prevention and control strategies. MethodsDescriptive statistical method was used to analyze data on daily infections released by the Shanghai Municipal Health Commission from March 1 to June 30， 2022. ResultsAs of 30 June， a total of 627 110 infections and 588 deaths had been reported in Shanghai. Most of the cases were in Pudong New Area （35.47%）， Minhang District （10.18%） and Huangpu District （9.27%）. The cumulative infection rate was 8.78% in Huangpu District， which was the highest among all the districts. With the progress of the pandemic， the prevention and control measures were strengthened from a “precise prevention and control” strategy to “block and grid” screening， and then upgraded to city-wide lockdown. All daily new infections were identified from the quarantined population on April 29， 2022， reaching the goal of “clearance of community transmission”. ConclusionThe cumulative infections in Shanghai exceeded any previous epidemics in mainland China. Given the enhanced transmissibility and vaccine-induced immune escape of the Omicron variant， timely and strong public health measures are needed to suppress the pandemic under the general policy of "Dynamic zero-COVID".

Pharmacodynamics of human interferon α1b against severe acute respiratory syndrome coronavirus 2 Omicron strain in vitro / 中国生物制品学杂志

@#Objective To evaluate the pharmacodynamics of human interferon(IFN)α1b against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron strain in vitro.Methods Total four drugs human IFNα1b bulk,human IFNα1b eye drops,human IFNα1b spray and Remdesivir were detected for cytotoxicity by CCK-8 assay.The inhibitory effect of human IFNα1b on SARS-CoV-2 Omicron strains(BA.5/BA.2/BA.1)was determined by qPCR.Results Human IFNα1b bulk of the maximum concentration(1 × 107IU/mL)and Remdesivir of the maximum concentration(150 μmol/L)did not achieve half cytotoxicity to Vero cells;The median cytotoxicity concentrations(CC_(50))of human IFNα1b eye drops and human IFNα1b sprays were 29 958 and 37 550 IU/mL,respectively,showing toxicity to Vero cells.The median effective concentrations(EC_(50))of human IFNα1b against virus strains BA.1,BA.2 and BA.5 after incubation for 2 h in advance were 9.30,13.38 and 12.33 IU/mL and those of Remdesivir were 0.314 7,0.291 0 and0.300 3 μmol/L.When incubation with virus simultaneously,the EC_(50)of human IFNα1b to BA.1,BA.2 and BA.5 were19.68,10.91 and 18.84 IU/mL and those of the control drug Remdesivir were 0.320 5,0.274 4 and 0.304 1 μmol/L,respectively.Conclusion At the cell level in vitro,human IFNα1b of very low activity showed a good inhibitory effect on SARS-CoV-2 Omicron strain,which was expected to be a clinical specific drug for the treatment of SARS-CoV-2 Omicron strain infection.

Research Status of SARS-CoV-2 Omicron Variant-infected Pregnant Women / 中山大学学报(医学科学版)

The new variant B.1.1.529 of COVID-19 was reported to the WHO for the first time by South Africa on November 24， 2021. At present， Omicron has become the dominant strain in the world and is spreading rapidly. Although Omicron infected during pregnancy shows the lower risk of serious maternal and fetal complications than the previous variants and Delta variant， the rapid increase in the number of cases and the wide range of patients still worth attention of obstetricians. This article reviews the prevalence of Omicron variant infection， the clinical characteristics ， the prevention and the treatment of pregnant women infected with Omicron， as well as the breastfeeding of newborns. It is believed that Omicron infection will not increase the rate of early spontaneous abortion and the infant congenital malformations， but it may increase the risk of gestational hypertensive disorders， premature delivery， cesarean section， and postpartum hemorrhage in the third trimester of pregnancy.We put forward corresponding management strategies and suggestions to provide references for the diagnosis and treatment of novel coronavirus infection in pregnant women in China.

Efficacy and Safety of Huashi Baidu Granules in Treating Patients with SARS-CoV-2 Omicron Variant: A Single-Center Retrospective Cohort Study / 中国结合医学杂志

OBJECTIVE@#To evaluate the efficacy and safety of Huashi Baidu Granules (HSBD) in treating patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant.@*METHODS@#A single-center retrospective cohort study was conducted during COVID-19 Omicron epidemic in the Mobile Cabin Hospital of Shanghai New International Expo Center from April 1st to May 23rd, 2022. All COVID-19 patients with asymptomatic or mild infection were assigned to the treatment group (HSBD users) and the control group (non-HSBD users). After propensity score matching in a 1:1 ratio, 496 HSBD users of treatment group were matched by propensity score to 496 non-HSBD users. Patients in the treatment group were administrated HSBD (5 g/bag) orally for 1 bag twice a day for 7 consecutive days. Patients in the control group received standard care and routine treatment. The primary outcomes were the negative conversion time of nucleic acid and negative conversion rate at day 7. Secondary outcomes included the hospitalized days, the time of the first nucleic acid negative conversion, and new-onset symptoms in asymptomatic patients. Adverse events (AEs) that occurred during the study were recorded. Further subgroup analysis was conducted in vaccinated (378 HSBD users and 390 non-HSBD users) and unvaccinated patients (118 HSBD users and 106 non-HSBD users).@*RESULTS@#The median negative conversion time of nucleic acid in the treatment group was significantly shortened than the control group [3 days (IQR: 2-5 days) vs. 5 days (IQR: 4-6 days); P<0.01]. The negative conversion rate of nucleic acid in the treatment group were significantly higher than those in the control group at day 7 (91.73% vs. 86.90%, P=0.014). Compared with the control group, the hospitalized days in the treatment group were significantly reduced [10 days (IQR: 8-11 days) vs. 11 days (IQR: 10.25-12 days); P<0.01]. The time of the first nucleic acid negative conversion had significant differences between the treatment and control groups [3 days (IQR: 2-4 days) vs. 5 days (IQR: 4-6 days); P<0.01]. The incidence of new-onset symptoms including cough, pharyngalgia, expectoration and fever in the treatment group were lower than the control group (P<0.05 or P<0.01). In the vaccinated patients, the median negative conversion time and hospitalized days were significantly shorter than the control group after HSDB treatment [3 days (IQR: 2-5 days) vs. 5 days (IQR: 4-6 days), P<0.01; 10 days (IQR: 8-11 days) vs. 11 days (IQR: 10-12 days), P<0.01]. In the unvaccinated patients, HSBD treatment efficiently shorten the median negative conversion time and hospitalized days [4 days (IQR: 2-6 days) vs. 5 days (IQR: 4-7 days), P<0.01; 10.5 days (IQR: 8.75-11 days) vs. 11.0 days (IQR: 10.75-13 days); P<0.01]. No serious AEs were reported during the study.@*CONCLUSION@#HSBD treatment significantly shortened the negative conversion time of nuclear acid, the length of hospitalization, and the time of the first nucleic acid negative conversion in patients infected with SARS-COV-2 Omicron variant (Trial registry No. ChiCTR2200060472).

Clinical characteristics of neonates infected with the Omicron variant of SARS-CoV-2: a multicenter cross-sectional survey / 中国当代儿科杂志

OBJECTIVES@#To investigate the clinical characteristics of neonates infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).@*METHODS@#A cross-sectional survey was conducted on 542 hospitalized neonates with confirmed coronavirus disease 2019 (COVID-19) in 27 hospitals in Shenzhen from December 7, 2022, to January 12, 2023 (during the Omicron variant epidemic period). The neonates were divided into two groups: asymptomatic infection and symptomatic infection. The clinical characteristics, results of laboratory examination, chest X-ray findings, and outcome were compared between the two groups.@*RESULTS@#Among the 542 neonates, there were 285 males and 257 females. Among them, 515 (95.0%) were full-term infants, and 27 (5.0%) were preterm infants. The asymptomatic infection group had 60 cases, and the symptomatic infection group had 482 cases. Among them, 336 cases (69.7%) were mild, 125 cases (25.9%) were moderate, 15 cases (3.1%) were severe, and 6 cases (1.2%) were critical. Fever was the most common symptom (434 cases, 90.0%), followed by cough and/or spitting (183 cases, 38.0%), nasal congestion and/or runny nose (131 cases, 27.2%), shortness of breath (36 cases, 7.5%), and feeding intolerance (30 cases, 6.2%). Among the 325 cases who underwent chest X-ray examination, 136 cases (41.8%) had patchy or consolidative shadows in the lungs, 2 cases (0.6%) had pneumothorax, 2 cases (0.6%) had decreased lung transparency, and 185 cases (57.0%) showed no abnormality. Among the 396 cases (73.1%) who received treatment, 341 cases (86.1%) received symptomatic treatment, 137 cases (34.6%) received antibiotic treatment, 4 cases (1.0%) received immunoglobulin treatment, and 23 cases (5.8%) received respiratory support treatment. All 542 neonates were discharged from the hospital after their clinical symptoms were relieved, and the median hospital stay was 5 days. The white blood cell count, neutrophil count, hemoglobin, and procalcitonin were lower in the symptomatic infection group than those in the asymptomatic infection group (P<0.05), while the platelet count and blood glucose levels were higher in the symptomatic infection group than those in the asymptomatic infection group (P<0.05). The proportions of neonates with decreased neutrophil count, increased platelet count, and decreased hemoglobin concentration were higher in the symptomatic infection group than those in the asymptomatic group (P<0.05).@*CONCLUSIONS@#Most neonates with COVID-19 caused by the Omicron variant of SARS-CoV-2 are mild, with fever as the predominant symptom. Symptomatic neonates with COVID-19 are often accompanied by decreased neutrophil count, increased platelet count, and decreased hemoglobin level. Symptomatic treatment is the main treatment, and the prognosis is good.

Clinical features of children with coronavirus disease 2019 in different age groups during the epidemic of Omicron variant / 中国当代儿科杂志

OBJECTIVES@#To study the differences in the clinical features of children with coronavirus disease 2019 (COVID-19) in different age groups during the epidemic of Omicron variant.@*METHODS@#A retrospective analysis was performed on the clinical data of 211 children with COVID-19 who were admitted to the Department of General Pediatrics, Zhongshan People's Hospital, from December 9, 2022 to January 8, 2023. According to their age, they were divided into 4 groups: 1 month-<1 year (n=84), 1-<3 years group (n=64), 3-<5 years (n=29), and ≥5 years (n=34). The above groups were compared in terms of general status, clinical features, ancillary examination results, treatment, and outcome.@*RESULTS@#The children aged <3 years accounted for 70.1% (148/211) of all hospitalized children with COVID-19, and the 3-<5 years group and the ≥5 years group had a significantly higher proportion of children with underlying diseases than the 1 month-<1 year group and the 1-<3 years group (P<0.05). Compared with the other three groups, the 1 month-<1 year group had significantly higher incidence rates of dyspnea, nasal congestion/nasal discharge, diarrhea and significantly lower incidence rates of convulsion and nervous system involvement (P<0.05). Moreover, compared with the other three groups, the 1 month-<1 year group had significantly higher incidence rates of increases in bile acid and creatine kinase isoenzyme and significantly lower incidence rates of decreased platelet count, increased neutrophil percentage, and decreased lymphocyte percentage (P<0.05). The 1 month-<1 year group had a significantly higher incidence rate of mild COVID-19 than the 1-<3 years group and a significantly lower incidence rate of severe/critical COVID-19 than the other three groups (P<0.05). Compared with the other three groups, the 1 month-<1 year group had a significantly higher proportion of children receiving oxygen inhalation therapy (P<0.05).@*CONCLUSIONS@#Children with COVID-19 in different age groups have different clinical features during the epidemic of Omicron variant, especially between the children aged 1 month to <1 year and those aged ≥1 year.

Clinical features of children with febrile seizures caused by Omicron variant infection / 中国当代儿科杂志

OBJECTIVES@#To study the clinical features of children with febrile seizures after Omicron variant infection.@*METHODS@#A retrospective analysis was performed on the clinical data of children with febrile seizures after Omicron variant infection who were admitted to the Department of Neurology, Children's Hospital Affiliated to the Capital Institute of Pediatrics, from December 1 to 31, 2022 (during the epidemic of Omicron variant; Omicron group), and the children with febrile seizures (without Omicron variant infection) who were admitted from December 1 to 31, in 2021 were included as the non-Omicron group. Clinical features were compared between the two groups.@*RESULTS@#There were 381 children in the Omicron group (250 boys and 131 girls), with a mean age of (3.2±2.4) years. There were 112 children in the non-Omicron group (72 boys and 40 girls), with a mean age of (3.5±1.8) years. The number of children in the Omicron group was 3.4 times that in the non-Omicron group. The proportion of children in two age groups, aged 1 to <2 years and 6-10.83 years, in the Omicron group was higher than that in the non-Omicron group, while the proportion of children in two age groups, aged 4 to <5 years and 5 to <6 years, was lower in the Omicron group than that in the non-Omicron group (P<0.05).The Omicron group had a significantly higher proportion of children with cluster seizures and status convulsion than the non-Omicron group (P<0.05). Among the children with recurrence of febrile seizures, the proportion of children aged 6-10.83 years in the Omicron group was higher than that in the non-Omicron group, while the proportion of children aged 3 years, 4 years, and 5 years in the Omicron group was lower than that in the non-Omicron group (P<0.05).@*CONCLUSIONS@#Children with febrile seizures after Omicron variant infection tend to have a wider age range, with an increase in the proportion of children with cluster seizures and status convulsion during the course of fever.

Clinical features of 23 neonates infected with Omicron variant of severe acute respiratory syndrome coronavirus 2 / 中国当代儿科杂志

OBJECTIVES@#To summarize the clinical features of neonates infected with Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).@*METHODS@#The medical data of 23 neonates with Omicron variant of SARS-CoV-2 infection admitted to the City North Campus of Urumqi First People's Hospital from October to December 2022 were retrospectively reviewed.@*RESULTS@#All 23 infants had a history of exposure to confirmed caregivers with SARS-CoV-2 infection after birth, and none of them was vertically transmitted. Clinical classification: 5 cases of asymptomatic infection, 18 cases of mild infection, and no cases of moderate, severe, or critically ill. The first symptoms were fever in 13 cases, cough in 3 cases, nasal congestion in 1 case, and diarrhea in 1 case. Blood white blood cell counts decreased in 2 cases, and C-reactive protein increased in 1 case. Seven infants underwent chest X-ray examination due to cough or shortness of breath, and one of which showed focal exudative changes, while the rest showed no abnormal changes. All infants were discharged after symptomatic treatment and the median hospital stay was 6 days. The duration of nucleic acid positivity of SARS-CoV-2 was negatively correlated with N gene Ct values and ORF1ab gene Ct values (rs=-0.719 and -0.699, respectively; P<0.05). One month after discharge, all infants had no symptoms or signs of nucleic acid re-positivity.@*CONCLUSIONS@#The clinical manifestations are usually mild or asymptomatic in neonates infected with SARS-CoV-2 Omicron variant. The lower the Ct values of the N and ORF1ab genes of SARS-CoV-2, the longer the duration of nucleic acid positivity. Neonates infected with SARS-CoV-2 Omicron variant can have a good prognosis after symptomatic treatment.

Neutralizing Antibody Responses against Five SARS-CoV-2 Variants and T Lymphocyte Change after Vaccine Breakthrough Infections from the SARS-CoV-2 Omicron BA.1 Variant in Tianjin, China: A Prospective Study / 生物医学与环境科学（英文）

OBJECTIVE@#To investigate whether Omicron BA.1 breakthrough infection after receiving the SARS-CoV-2 vaccine could create a strong immunity barrier.@*METHODS@#Blood samples were collected at two different time points from 124 Omicron BA.1 breakthrough infected patients and 124 controls matched for age, gender, and vaccination profile. Live virus-neutralizing antibodies against five SARS-CoV-2 variants, including WT, Gamma, Beta, Delta, and Omicron BA.1, and T-lymphocyte lymphocyte counts in both groups were measured and statistically analyzed.@*RESULTS@#The neutralizing antibody titers against five different variants of SARS-CoV-2 were significantly increased in the vaccinated population infected with the Omicron BA.1 variant at 3 months after infection, but mainly increased the antibody level against the WT strain, and the antibody against the Omicron strain was the lowest. The neutralizing antibody level decreased rapidly 6 months after infection. The T-lymphocyte cell counts of patients with mild and moderate disease recovered at 3 months and completely returned to the normal state at 6 months.@*CONCLUSION@#Omicron BA.1 breakthrough infection mainly evoked humoral immune memory in the original strain after vaccination and hardly produced neutralizing antibodies specific to Omicron BA.1. Neutralizing antibodies against the different strains declined rapidly and showed features similar to those of influenza. Thus, T-lymphocytes may play an important role in recovery.

Rapid detection and genotyping of SARS-CoV-2 Omicron BA.4/5 variants using a RT-PCR and CRISPR-Cas12a-based assay / 南方医科大学学报

OBJECTIVE@#To establish a rapid detection and genotyping method for SARS-CoV-2 Omicron BA.4/5 variants using CRISPPR-Cas12a gene editing technology.@*METHODS@#We combined reverse transcription-polymerase chain reaction (RT-PCR) and CRISPR gene editing technology and designed a specific CRISPPR RNA (crRNA) with suboptimal protospacer adjacent motifs (PAM) for rapid detection and genotyping of SARS- CoV-2 Omicron BA.4/5 variants. The performance of this RT- PCR/ CRISPPR-Cas12a assay was evaluated using 43 clinical samples of patients infected by wild-type SARS-CoV-2 and the Alpha, Beta, Delta, Omicron BA. 1 and BA. 4/5 variants and 20 SARS- CoV- 2-negative clinical samples infected with 11 respiratory pathogens. With Sanger sequencing method as the gold standard, the specificity, sensitivity, concordance (Kappa) and area under the ROC curve (AUC) of RT-PCR/CRISPPR-Cas12a assay were calculated.@*RESULTS@#This assay was capable of rapid and specific detection of SARS- CoV-2 Omicron BA.4/5 variant within 30 min with the lowest detection limit of 10 copies/μL, and no cross-reaction was observed in SARS-CoV-2-negative clinical samples infected with 11 common respiratory pathogens. The two Omicron BA.4/5 specific crRNAs (crRNA-1 and crRNA-2) allowed the assay to accurately distinguish Omicron BA.4/5 from BA.1 sublineage and other major SARS-CoV-2 variants of concern. For detection of SARS-CoV-2 Omicron BA.4/5 variants, the sensitivity of the established assay using crRNA-1 and crRNA-2 was 97.83% and 100% with specificity of 100% and AUC of 0.998 and 1.000, respectively, and their concordance rate with Sanger sequencing method was 92.83% and 96.41%, respectively.@*CONCLUSION@#By combining RT-PCR and CRISPPR-Cas12a gene editing technology, we successfully developed a new method for rapid detection and identification of SARS-CoV-2 Omicron BA.4/5 variants with a high sensitivity, specificity and reproducibility, which allows rapid detection and genotyping of SARS- CoV-2 variants and monitoring of the emerging variants and their dissemination.