Variant In China Research Articles

Impacts of COVID-19 vaccine boosters on clinical outcomes associated with the Omicron variant in China: A cross-sectional survey

ObjectiveTo investigate the real-world effectiveness of COVID-19 vaccine boosters during China’s Omicron wave. MethodsIn January 2023, we surveyed Shenzhen, China residents via online questionnaires to investigate their COVID-19 symptoms and vaccination history. The outcomes of interest included fever, other COVID-19-related symptoms, severity of symptoms, whether early onset (before December 23, 2022) and duration. Respondents were categorized as no booster, one booster 6mo ago, one booster within 6mo, or two boosters based on dose count and vaccination timing. We used multivariable logistic regressions and Tobit models to assess COVID-19 vaccine booster impacts. ResultsCompared to the no booster group, two booster recipients had a lower fever risk (OR = 0.35, 95 %CI = 0.16–0.76) but not lower risks of COVID-19-related symptoms (OR = 0.74, 95 %CI = 0.26–2.06) and self-reported severe symptoms (OR = 0.47, 95 %CI = 0.19–1.15). Nor did the two booster recipients had a shorter illness duration (marginal effect = -0.79 days, 95 %CI = -1.65–0.07) and a lower risk of symptom onset delay (OR = 0.48, 95 %CI = 0.19–1.23). Compared to the no booster group, both one booster within six months (OR = 2.17, 95 %CI = 1.34–3.52) and one booster six months ago (OR = 1.30, 95 %CI = 0.92–1.82) did not reduce the risks of fever and symptoms (one booster within six months: OR = 1.57, 95 %CI = 0.84–2.90; one booster six months ago: OR = 1.23, 95 %CI = 0.79–1.93). Regardless of timing, one booster did not reduce illness duration (within six months: marginal effect = 0.25 days, 95 %CI = -0.20–0.70; six months ago: marginal effect = 0.27 days, 95 %CI = -0.08–0.62). However, receiving one booster within six months delayed symptom onset (OR = 0.54, 95 %CI = 0.34–0.86), while one booster six months ago did not (OR = 1.03, 95 %CI = 0.74–1.44). ConclusionsReceiving two booster doses reduced the onset of fever during the Omicron outbreak in mainland China.

Distinct SARS-CoV-2 populational immune backgrounds tolerate divergent RBD evolutionary preferences.

Immune evasion is a pivotal force shaping the evolution of viruses. Nonetheless, the extent to which virus evolution varies among populations with diverse immune backgrounds remains an unsolved mystery. Prior to the widespread SARS-CoV-2 infections in December 2022 and January 2023, the Chinese population possessed a markedly distinct (less potent) immune background due to its low infection rate, compared to countries experiencing multiple infection waves, presenting an unprecedented opportunity to investigate how the virus has evolved under different immune contexts. We compared the mutation spectrum and functional potential of the newly derived mutations that occurred in BA.5.2.48, BF.7.14 and BA.5.2.49-variants prevalent in China-with their counterparts in other countries. We found that the emerging mutations in the receptor-binding-domain region in these lineages were more widely dispersed and evenly distributed across different epitopes. These mutations led to a higher angiotensin-converting enzyme 2 (ACE2) binding affinity and reduced potential for immune evasion compared to their counterparts in other countries. These findings suggest a milder immune pressure and less evident immune imprinting within the Chinese population. Despite the emergence of numerous immune-evading variants in China, none of them outcompeted the original strain until the arrival of the XBB variant, which had stronger immune evasion and subsequently outcompeted all circulating variants. Our findings demonstrated that the continuously changing immune background led to varying evolutionary pressures on SARS-CoV-2. Thus, in addition to viral genome surveillance, immune background surveillance is also imperative for predicting forthcoming mutations and understanding how these variants spread in the population.

Prevalence and diversity of imported severe acute respiratory syndrome coronavirus 2 variants in China, 2021-2022.

The causative agent of coronavirus disease 2019 (COVID-19), known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread accumulatively to 240 countries and continues to evolve. To gain a comprehensive understanding of the epidemiological characteristics of imported variants in China and their correlation with global circulating variants, genomic surveillance data from 11 139 imported COVID-19 cases submitted by Chinese provincial CDC laboratories between 2021 and 2022 were analyzed. Consensus sequences underwent rigorous quality checks, followed by amino acid mutations analysis using Nextclade. Sequences with satisfactory quality control status were classified according to the Pango nomenclature. The results showed that the dominant variants in imported cases reflected the global epidemic trend. An increase in the number of imported SARS-CoV-2 lineages monitored in China in the second half of 2022, and the circulating Omicron subvariants changed from the ancestral lineages of BA.5 and BA.2 into the lineages containing key amino acid mutations of spike protein. There was significant variation in the detection of Omicron subvariants among continents (χ2 = 321.968, p < 0.001) in the second half of 2022, with four lineages (BA.2.3.7, BA.2.2, BA.5.2.7, and XBB.1.2) identified through imported surveillance mainly prevalent respectively in Taiwan, China, Hong Kong SAR, China, Russian Federation, and Singapore. These findings revealed the alterations in circulating imported variants from 2021 to 2022 in China, reflecting the higher diversity of lineages in the second half of 2022, and revealed the predominant lineages of countries or regions that are in close contacts to China, providing new insights into the global prevalence of SARS-CoV-2.

Explosive household spread of the SARS-CoV-2 Omicron variant in China in late 2022

Immediately after easing the 3-year zero-COVID policy in mainland China, an explosive spread of the Omicron variant of SARS-CoV-2 occurred in late 2022, despite most people staying at home. We characterise the virus transmission within households and the associated risk factors. We conducted an online survey, which was done by professors and postgraduate students in the discipline of building environment and energy engineering, and all questionnaires were completed on December 31, 2022 and collected over a period of 11 h. The self-reported infection status of 12,037 people in 4421 households was collected in mainland China. Data on vaccination status, mask wearing, hand hygiene, ventilation, and bathroom air odours were analysed. Of the surveyed population, 79.2% (9533/12,037) reported infection based on symptoms or rapid test results by 31 December. The daily number of cases peaked on 20 December nationally and between 16 and 26 December in different provinces. Better ventilation in shared corridors and living rooms was associated with a lower household daily incidence rate and a lower fever occurrence. Residing on upper floors was associated with a higher daily incidence rate. Wearing an N95 respirator when leaving home could effectively reduce household infection risk. The observed similarity in the peak infection rate and its date of occurrence in different provincial regions suggest the spontaneous and simultaneous spread of the Omicron variant across the country. Crowded households, poor ventilation in shared common corridors, and residing on upper floors were associated with a higher incidence and more symptoms of disease.

Opportunistic pathogens increased and probiotics or short-chain fatty acid-producing bacteria decreased in the intestinal microbiota of pneumonia inpatients during SARS-CoV-2 Omicron variant epidemic.

The global pandemic of COVID-19 has been over four years, and the role of intestinal microbiota in the occurrence and development of COVID-19 needs to be further clarified. During the outbreak of SARS-CoV-2 Omicron variant in China, we analyzed the intestinal microbiome in fecal samples from inpatients with pneumonia and normal individuals in January 2023. The microbiota composition, alpha diversity, beta diversity, differential microbial community, co-occurrence networks, and functional abundance were analyzed. The results showed significant differences in microbiota composition between the two groups. In pneumonia group, the abundance of Bifidobacterium, Blautia, Clostridium, and Coprococcus decreased, while the abundance of Enterococcus, Lactobacillus, and Megamonas increased. Through LEfSe analysis, 37 marker microbiota were identified in pneumonia group. Co-occurrence network analysis found that Lachnospiraceae was critical for the interaction of intestinal microbiota, and the anti-inflammatory bacteria Blautia was negatively correlated with the pro-inflammatory bacteria Ruminococcus. Functional prediction found the up-regulation of steroid biosynthesis, geraniol degradation, and mRNA surveillance pathway in pneumonia group. In conclusion, opportunistic pathogens increased and probiotics, or short-chain fatty acid-producing bacteria, decreased in the intestinal microbiota of pneumonia inpatients during the Omicron epidemic. Blautia could be used as a probiotic in the treatment of pneumonia patients in the future.

Profiles of Cough and Associated Risk Factors in Nonhospitalized Individuals With SARS-CoV-2 Omicron Variant Infection: Cross-Sectional Online Survey in China.

Cough is a common symptom during and after COVID-19 infection; however, few studies have described the cough profiles of COVID-19. The aim of this study was to investigate the prevalence, severity, and associated risk factors of severe and persistent cough in individuals with COVID-19 during the latest wave of the Omicron variant in China. In this nationwide cross-sectional study, we collected information of the characteristics of cough from individuals with infection of the SARS-CoV-2 Omicron variant using an online questionnaire sent between December 31, 2022, and January 11, 2023. There were 11,718 (n=7978, 68.1% female) nonhospitalized responders, with a median age of 37 (IQR 30-47) years who responded at a median of 16 (IQR 12-20) days from infection onset to the time of the survey. Cough was the most common symptom, occurring in 91.7% of participants, followed by fever, fatigue, and nasal congestion (68.8%-87.4%). The median cough visual analog scale (VAS) score was 70 (IQR 50-80) mm. Being female (odds ratio [OR] 1.31, 95% CI 1.20-1.43), having a COVID-19 vaccination history (OR 1.71, 95% CI 1.37-2.12), current smoking (OR 0.48, 95% CI 0.41-0.58), chronic cough (OR 2.04, 95% CI 1.69-2.45), coronary heart disease (OR 1.71, 95% CI 1.17-2.52), asthma (OR 1.22, 95% CI 1.02-1.46), and gastroesophageal reflux disease (GERD) (OR 1.21, 95% CI 1.01-1.45) were independent factors for severe cough (VAS>70, 37.4%). Among all respondents, 35.0% indicated having a productive cough, which was associated with risk factors of being female (OR 1.44, 95% CI 1.31-1.57), having asthma (OR 1.84, 95% CI 1.52-2.22), chronic cough (OR 1.44, 95% CI 1.19-1.74), and GERD (OR 1.22, 95% CI 1.01-1.47). Persistent cough (>3 weeks) occurred in 13.0% of individuals, which was associated with the risk factors of having diabetes (OR 2.24, 95% CI 1.30-3.85), asthma (OR 1.70, 95% CI 1.11-2.62), and chronic cough (OR 1.97, 95% CI 1.32-2.94). Cough is the most common symptom in nonhospitalized individuals with Omicron SARS-CoV-2 variant infection. Being female, having asthma, chronic cough, GERD, coronary heart disease, diabetes, and a COVID-19 vaccination history emerged as independent factors associated with severe cough, productive cough, and persistent cough.

Carrier frequencies, trends, and geographical distribution of hearing loss variants in China: The pooled analysis of 2,161,984 newborns

ObjectiveThe aim of this study is to comprehensively investigate the prevalence and distribution patterns of three common genetic variants associated with hearing loss (HL) in Chinese neonatal population. Methods: Prior to June 30, 2023, an extensive search and screening process was conducted across multiple literature databases. R software was utilized for conducting meta-analyses, cartography, and correlation analyses. Results: Firstly, our study identified a total of 99 studies meeting the inclusion criteria. Notably, provinces such as Qinghai, Tibet, Jilin, and Heilongjiang lack large-scale genetic screening data for neonatal deafness. Secondly, in Chinese newborns, the carrier frequencies of GJB2 variants (c.235delC, c.299_300delAT) were 1.63 % (95 %CI 1.52 %–1.76 %) and 0.33 % (95 %CI 0.30 %–0.37 %); While SLC26A4 variants (c.919-2A > G, c.2168A > G) exhibited carrier rates of 0.95 % (95 %CI 0.86 %–1.04 %) and 0.17 % (95 %CI 0.15 %–0.19 %); Additionally, Mt 12S rRNA m.1555 A > G variant was found at a rate of 0.24 % (95 % CI 0.22 %–0.26 %). Thirdly, the mutation rate of GJB2 c.235delC was higher in the east of the Heihe-Tengchong line, whereas the mutation rate of Mt 12S rRNA m.1555 A > G variant exhibited the opposite pattern. Forthly, no significant correlation exhibited the opposite pattern of GJB2 variants, but there was a notable correlation among SLC26A4 variants. Lastly, strong regional distribution correlations were evident between mutation sites from different genes, particularly between SLC26A4 (c.919-2A > G and c.2168A > G) and GJB c.299_300delAT. Conclusions: The most prevalent deafness genes among Chinese neonates were GJB2 c.235delC variant, followed by SLC26A4 c.919-2A > G variant. These gene mutation rates exhibit significant regional distribution characteristics. Consequently, it is imperative to enhance genetic screening efforts to reduce the incidence of deafness in high-risk areas.

Frequency and risk factors of psychological distress among individuals with epilepsy before and during the outbreak of the SARS-CoV-2 Omicron variant in China: an online questionnaire survey

BackgroundThe COVID-19 pandemic substantially increases the risk of severe psychological distress among people with epilepsy (PWE), especially those with monthly household income < 5000 RMB or with uncontrolled seizures. Patients with Kessler scores > 12 should consult a psychiatrist, especially during major disasters. This study was aimed to compare the frequency of psychological distress among Chinese PWE before and during the outbreak of the SARS-CoV-2 Omicron variant, and to identify risk factors for such distress.MethodsIn this prospective study, we collected sociodemographic data of PWE aged > 14 years, who were treated at our center during December 1 to 15, 2022. All participants completed the 6-item Kessler Psychological Distress Scale before the outbreak and again during the outbreak. Health visitors who were unrelated to those patients during the outbreak were included as a control. Multivariate logistic regression analysis was performed to identify risk factors of severe psychological distress and its exacerbation.ResultsOf the 223 PWE, 127 were tested positive for SARS-CoV-2, while 174 of 218 controls were positive for SARS-CoV-2. The neurological symptoms were similar between PWE and controls with SARS-CoV-2. The average Kessler score of PWE was significantly higher during the outbreak than before it (9.93 ± 3.98 vs. 8.52 ± 0.23, P < 0.001). The average score of controls during the outbreak (5.146 ± 0.35, P < 0.001) was significantly lower than that of the PWE. We identified three independent predictors for severe psychological distress in PWE during the outbreak, i.e., monthly household income < 5000 RMB (OR = 0.252, 95%CI 0.064–0.998, P = 0.048), severe psychological distress before the outbreak (OR = 0.067, 95%CI 0.026–0.174, P < 0.001), and seizure onset within 30 days before the assessment during the outbreak (OR = 0.356, 95%CI 0.157–0.805, P = 0.013). Of the three predictors, the last one was also an independent predictor for exacerbation of psychological distress during the outbreak (OR = 0.302, 95%CI 0.123–0.741, P = 0.009).ConclusionsOur analysis suggests that the COVID-19 pandemic has substantially increased psychological distress of individuals with epilepsy, regardless of the viral infection or not. Various neurological symptoms similar to those of “long COVID” appeared for the first time among these individuals during the Omicron outbreak, highlighting the need for clinicians to screen carefully for this condition. Management of epilepsy during the pandemic or a similar major disaster should focus on the control of seizures and maintenance of mental health, especially among those with monthly household incomes below 5000 RMB, suffering uncontrolled seizures and having a history of severe psychological distress.

Comparative epidemiology of outbreaks caused by SARS-CoV-2 Delta and Omicron variants in China.

From 2020 to December 2022, China implemented strict measures to contain the spread of severe acute respiratory syndrome coronavirus 2. However, despite these efforts, sustained outbreaks of the Omicron variants occurred in 2022. We extracted COVID-19 case numbers from May 2021 to October 2022 to identify outbreaks of the Delta and Omicron variants in all provinces of mainland China. We found that omicron outbreaks were more frequent (4.3 vs. 1.6 outbreaks per month) and longer-lasting (mean duration: 13 vs. 4weeks per outbreak) than Delta outbreaks, resulting in a total of 865,100 cases, of which 85% were asymptomatic. Despite the average Government Response Index being 12% higher (95% confidence interval (CI): 9%, 15%) in Omicron outbreaks, the average daily effective reproduction number (Rt) was 0.45 higher (95% CI: 0.38, 0.52, p<0.001) than in Delta outbreaks. Omicron outbreaks were suppressed in 32days on average (95% CI: 26, 39), which was substantially longer than Delta outbreaks (14days; 95% CI: 11, 19; p=0.004). We concluded that control measures effective against Delta could not contain Omicron outbreaks in China. This highlights the need for continuous evaluation of new variants' epidemiology to inform COVID-19 response decisions.

JN.1: enhanced immune evasion ability propels it to become the predominant strain in China, unlikely to trigger pandemic similar to late 2022.

Due to the widespread presence of susceptible populations, the pandemic caused by BA.5 subbranches swiftly disseminated China, impacting the majority of individuals within a span of 1 to 2 months. Subsequently, XBB and its subbranches became the dominant variants in China. We tracked the immune landscape in the population after the SARS-CoV-2 pandemic in late 2022 in China. Our findings suggested that low levels of neutralizing antibodies against BA.5 subbranches before the pandemic might have contributed to the national outbreak at the end of 2022. The widespread breakthrough infections subsequently increased immunity to BA.5, XBB.1.5/1.9.1, and JN.1, inhibiting a new wave of large-scale infections caused by XBB subbranches in China. Additionally, JN.1 demonstrated enhanced immune evasion capabilities; however, Chinese residents had comparable levels of neutralizing antibodies against JN.1 as those observed for XBB.1.5 among confirmed cases at the end of 2022. We anticipate that JN.1 will replace XBB subbranches as the predominant epidemic variant in subsequent transmissions within China. However, it is unlikely to cause a large-scale spread comparable to that witnessed at the end of 2022, with transmission patterns potentially resembling those observed for XBB post-pandemic.

The attenuated African swine fever vaccine HLJ/18-7GD provides protection against emerging prevalent genotype II variants in China

ABSTRACT Genetic changes have occurred in the genomes of prevalent African swine fever viruses (ASFVs) in the field in China, which may change their antigenic properties and result in immune escape. There is usually poor cross-protection between heterogonous isolates, and, therefore, it is important to test the cross-protection of the live attenuated ASFV vaccines against current prevalent heterogonous isolates. In this study, we evaluated the protective efficacy of the ASFV vaccine candidate HLJ/18-7GD against emerging isolates. HLJ/18-7GD provided protection against a highly virulent variant and a lower lethal isolate, both derived from genotype II Georgia07-like ASFV and isolated in 2020. HLJ/18-7GD vaccination prevented pigs from developing ASF-specific clinical signs and death, decreased viral shedding via the oral and rectal routes, and suppressed viral replication after challenges. However, HLJ/18-7GD vaccination did not provide solid cross-protection against genotype I NH/P68-like ASFV challenge in pigs. HLJ/18-7GD vaccination thus shows great promise as an alternative strategy for preventing and controlling genotype II ASFVs, but vaccines providing cross-protection against different ASFV genotypes may be needed in China.

Chinese expert consensus on the management of patients with hematologic malignancies infected with SARS-CoV-2.

In December 2022, the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became dominant in China due to its high infectivity and lower mortality rate. The risk of critical illness and mortality among patients with hematologic malignancies who contracted SARS-CoV-2 was particularly high. The aim of this study was to draft a consensus to facilitate effective treatments for these patients based on the type and severity of the disease. Following the outbreak of the novel coronavirus in China, a steering committee consisting of experienced hematologists was formed by the Specialized Committee of Oncology and Microecology of the Chinese Anti-Cancer Association. The expert group drafted a consensus on the management and intervention measures for different types of hematologic malignancies based on the clinical characteristics of the Omicron variant of the SARS-CoV-2 infection, along with relevant guidelines and literature. The expert group drafted independent recommendations on several important aspects based on the epidemiology of the Omicron variant in China and the unique vulnerability of patients with hematologic malignancies. These included prophylactic vaccinations for those with hematologic malignancies, the use of plasma from blood donors who recovered from the novel coronavirus infection, the establishment of negative pressure wards, the use of steady-state mobilization of peripheral blood hematopoietic stem cells, the provision of psychological support for patients and medical staff, and a focus on maintaining a healthy intestinal microecology.

Effect of tixagevimab/cilgavimab for pre-exposure prophylaxis during the China Omicron outbreak

ABSTRACT Objectives By the end of 2022, China had made a pivotal decision to optimize the COVID-19 policy. The dominant Omicron variant in China at that time was highly transmissible. In this study, we aimed to evaluate the real-world safety and efficacy of tixagevimab and cilgavimab against this background in China. Methods Participants were enrolled if they were over 12 years old and were planning to receive tixagevimab or cilgavimab. All participants received intramuscular administration of tixagevimab (150 mg) and cilgavimab (150 mg). Data were collected on demographics, underlying illness, prior infection, vaccination, adverse events, and COVID-19 outcomes (e.g., infection rate, hospitalization rate, and severe disease). Results During the study period, 168 (37.9%) of 443 who received tixagevimab/cilgavimab were diagnosed with SARS-CoV-2 infection. All infected patients had mild COVID-19. Two patients (0.5%) were hospitalized for COVID-19, but none of them were admitted to the ICU. None of the patients died during this study. 4 (0.9%) reported mild local adverse events, and no severe systemic adverse reactions were reported. Conclusion Tixagevimab/cilgavimab may have protected high-risk populations against infection with the Omicron variant, hospitalization and severe disease during the China COVID-19 pandemic.

Multidimensional dynamic prediction model for hospitalized patients with the omicron variant in China

PurposeTo establish dynamic prediction models by machine learning using daily multidimensional data for coronavirus disease 2019 (COVID-19) patients. MethodsHospitalized COVID-19 patients at Peking Union Medical College Hospital from Nov 2nd, 2022, to Jan 13th, 2023, were enrolled in this study. The outcome was defined as deterioration or recovery of the patient's condition. Demographics, comorbidities, laboratory test results, vital signs, and treatments were used to train the model. To predict the following days, a separate XGBoost model was trained and validated. The Shapley additive explanations method was used to analyze feature importance. ResultsA total of 995 patients were enrolled, generating 7228 and 3170 observations for each prediction model. In the deterioration prediction model, the minimum area under the receiver operating characteristic curve (AUROC) for the following 7 days was 0.786 (95% CI 0.721–0.851), while the AUROC on the next day was 0.872 (0.831–0.913). In the recovery prediction model, the minimum AUROC for the following 3 days was 0.675 (0.583–0.767), while the AUROC on the next day was 0.823 (0.770–0.876). The top 5 features for deterioration prediction on the 7th day were disease course, length of hospital stay, hypertension, and diastolic blood pressure. Those for recovery prediction on the 3rd day were age, D-dimer levels, disease course, creatinine levels and corticosteroid therapy. ConclusionThe models could accurately predict the dynamics of Omicron patients’ conditions using daily multidimensional variables, revealing important features including comorbidities (e.g., hyperlipidemia), age, disease course, vital signs, D-dimer levels, corticosteroid therapy and oxygen therapy.

Transmission dynamics informed neural network with application to COVID-19 infections

Since the end of 2019 the COVID-19 repeatedly surges with most countries/territories experiencing multiple waves, and mechanism-based epidemic models played important roles in understanding the transmission mechanism of multiple epidemic waves. However, capturing temporal changes of the transmissibility of COVID-19 during the multiple waves keeps ill-posed problem for traditional mechanism-based epidemic compartment models, because that the transmission rate is usually assumed to be specific piecewise functions and more parameters are added to the model once multiple epidemic waves involved, which poses a huge challenge to parameter estimation. Meanwhile, data-driven deep neural networks fail to discover the driving factors of repeated outbreaks and lack interpretability. In this study, aiming at developing a data-driven method to project time-dependent parameters but also merging the advantage of mechanism-based models, we propose a transmission dynamics informed neural network (TDINN) by encoding the SEIRD compartment model into deep neural networks. We show that the proposed TDINN algorithm performs very well when fitting the COVID-19 epidemic data with multiple waves, where the epidemics in the United States, Italy, South Africa, and Kenya, and several outbreaks the Omicron variant in China are taken as examples. In addition, the numerical simulation shows that the trained TDINN can also perform as a predictive model to capture the future development of COVID-19 epidemic. We find that the transmission rate inferred by the TDINN frequently fluctuates, and a feedback loop between the epidemic shifting and the changes of transmissibility drives the occurrence of multiple waves. We observe a long response delay to the implementation of control interventions in the four countries, while the decline of the transmission rate in the outbreaks in China usually happens once the implementation of control interventions. The further simulation show that 17 days’ delay of the response to the implementation of control interventions lead to a roughly four-fold increase in daily reported cases in one epidemic wave in Italy, which suggest that a rapid response to policies that strengthen control interventions can be effective in flattening the epidemic curve or avoiding subsequent epidemic waves. We observe that the transmission rate in the outbreaks in China is already decreasing before enhancing control interventions, providing the evidence that the increasing of the epidemics can drive self-conscious behavioural changes to protect against infections.

Addressing the risk of a new wave: managing COVID-19 cases associated with XBB variants in china - a correspondence.

Addressing the risk of a new wave: managing COVID-19 cases associated with XBB variants in china - a correspondence.

Critical national response in coping with Omicron variant in China, Israel, South Africa, and the United States.

The aim of this study was to analyze the effectiveness of prevention and control strategies and put forward further measures according to the epidemiological characteristics of Omicron. It summarized the national response during the Omicron epidemic in four countries: China, Israel, South Africa, and the United States. This study summarized prevention and control measures in China, Israel, South Africa, and the United States in their response to the Omicron epidemic, and it also evaluated the effectiveness of these measures. After the Omicron variant emerged, China and Israel adopted containment strategies, using the "dynamic zero" policy and country closure measures. Meanwhile, South Africa and the United States adopted mitigation strategies, which virtually abandoned social interventions and only focused on medical measures and vaccines. From the first day of reported Omicron cases to 28 February 2022, the four countries reported the following cases: China reported 9,670 new confirmed cases and no deaths, with total deaths per million of 3.21; Israel reported 2,293,415 new confirmed cases and 2,016 deaths, with total deaths per million of 1,097.21; South Africa reported 731,384 new confirmed cases and 9,509 deaths, with total deaths per million reaching 1,655.708; the United States reported 3,042,743 new confirmed cases and 1,688,851 deaths, with total deaths per million reaching 2,855.052, which was much higher than the other countries. Based on this study, it seems that China and Israel adopted containment strategies, while South Africa and the United States adopted mitigation strategies. A rapid response is a powerful weapon against the Omicron epidemic. Vaccines alone will not get any country out of this crisis, and non-pharmacological measures should be used in addition to them. According to the SPO model, future work should consider the strengthening of emergency management capacity, adhering to public health measures, promoting vaccination, and strengthening patient care and close contact management, which are effective measures in coping with Omicron.

The Role of “Hierarchical and Classified Prevention and Control Measures (HCPC)” Strategy for SARS-CoV-2 Delta Variant in Guangzhou: A Modeling Study

BackgroundThe Delta variant of SARS-COV-2 has replaced previously circulating strains around the world in 2021. Sporadic outbreaks of the Delta variant in China have posed a concern about how to properly respond to the battle against evolving COVID-19. Here, we analyzed the “hierarchical and classified prevention and control (HCPC)” measures strategy deployed during the recent Guangzhou outbreak.MethodsA modified susceptible–exposed–pre-symptomatic–infectious–recovered (SEPIR) model was developed and applied to study a range of different scenarios to evaluate the effectiveness of policy deployment. We simulated severe different scenarios to understand policy implementation and timing of implementation. Two outcomes were measured: magnitude of transmission and duration of transmission. The outcomes of scenario evaluations were presented relative to the reality case (i.e., 368 cases in 34 days) with 95% confidence interval (CI).ResultsBased on our simulation, the outbreak would become out of control with 7 million estimated infections under the assumption of the absence of any interventions than the 153 reported cases in reality in Guangzhou. The simulation on delayed implementation of interventions showed that the total case numbers would also increase by 166.67%–813.07% if the interventions were delayed by 3 days or 7 days.ConclusionsIt may be concluded that timely and more precise interventions including mass testing and graded community management are effective measures for Delta variant containment in China.

Clinical Characteristics of Mild Patients with Breakthrough Infection of Omicron Variant in China after Relaxing the Dynamic Zero COVID-19 Policy.

For SARS-CoV-2 mutants, the effectiveness of the COVID-19 vaccines is still controversial. In this study, we aimed to investigate the clinical characteristics of Omicron-infected patients who completed primary immunization and booster immunization, respectively, during the rapid propagation of the Omicron variant in China. A total of 932 patients with confirmed SARS-CoV-2 infection from 18 December 2022 to 1 January 2023 were included in this survey by filling out questionnaires online. The enrolled patients were divided into the primary immunization group and the booster immunization group according to their vaccination status. During the whole course of disease, the most frequent symptoms were fever (90.6%), cough (84.3%), weakness (77.4%), headache and dizziness (76.1%), and myalgia (73.9%). Nearly 90% of the patients had symptoms lasting for less than 10 days, and 39.8% of the patients ended the course of the disease in 4-6 days. A total of 58.8% of these patients had a fever with a maximum body temperature of over 38.5 °C. Moreover, 61.4% of the patients had a fever that lasted less than 2 days. There were no obvious differences in initial symptoms, cardinal symptoms, symptom duration time, maximum body temperature, and fever duration time between the two groups of patients. In addition, no significant difference was found in the positive or negative conversion time of SARS-CoV-2 antigen/nucleic acid between the two groups of patients. For mild patients with Omicron breakthrough infection, enhanced immunization has no significant impact on the clinical performance and duration of viral infection compared with primary immunization. The reasons behind the different clinical manifestations of patients with mild symptoms after the breakthrough infection of the Omicron strain are still worth further research. Heterologous vaccination may be a better strategy for enhanced immunization, which can help improve the immune protection ability of the population. Further research should be carried out on vaccines against mutant strains and spectral anti-COVID-19 vaccines.

Transfusion management of Africans with RHD variants in China.

The presence of D variant among minorities could produce a higher rate of alloimmunization observed in patients from this group. This is partly due to the ethnic and racial specificity of RHD variants and the limited availability of Rh-matched blood donors. Approximately half a million African migrants in China carrying distinct Rh blood type composition have presented to the health care system with an imperative safety requirement of blood transfusion among 1.3 billion Chinese individuals. We depict the clinically significant RHD alleles among African migrants living in China and identify the genetic similarities and disparities to Chinese. We discussed practical strategies to manage the unique transfusion needs of African migrants in China.