Influenza A(H3N2) is a contributor to seasonal epidemics, yet its evolution during and after the COVID-19 pandemic is not fully understood. We analyzed surveillance data and hemagglutinin (HA) and neuraminidase (NA) sequences from Hubei, China, 2017-2024. The epidemic followed regular seasonality before 2020, nearly disappeared during 2020-2022, and resurged with strong peaks after mid-2022. Multiple HA lineages co-circulated pre-pandemic. Several localized reassortment signals were observed before the pandemic, though overall evidence for intra-subtype reassortment remained limited. After resurgence, single dominant clades expanded, genetic diversity dropped, and clade turnover became clear. Bayesian coalescent analyses showed that effective population size had already declined by late 2019, before widespread SARS-CoV-2 transmission and interventions. Relaxed-clock and selection pressure analyses revealed heterogeneous HA substitution rates among lineages, likely reflecting differences in baseline substitution rates and the effects of transmission bottlenecks, rather than detectable shifts in selection intensity. Overall, HA and NA evolution was dominated by purifying selection, with a few sites in antigenic regions showing evidence of positive selection, coinciding with recurrent amino acid changes. Pre-pandemic population contraction, phase-specific rate variation, and site-specific antigenic adaptation shaped lineage turnover and epidemic patterns in Hubei. Monitoring population shifts, lineage-specific rates, and key antigenic substitutions can guide vaccine updates and strengthen preparedness.IMPORTANCEThe COVID-19 pandemic disrupted influenza activity worldwide, raising questions about its long-term effects on viral evolution. Our analysis of H3N2 in Hubei, China, shows that lineage contraction began before the pandemic and that post-pandemic evolutionary dynamics were shaped primarily by demographic processes, while purifying selection continued to dominate, with adaptive changes restricted to a limited number of antigenic sites. These findings suggest that intrinsic viral processes, not just pandemic restrictions, played a central role in shaping epidemic patterns and highlight the importance of continuous genomic surveillance to anticipate future outbreaks.

Drug therapy is an important measure to reduce the morbidity and mortality of influenza. However, small molecule drugs have inherent limitations, such as poor water solubility, non-specific biological distribution, and susceptibility to degradation during blood circulation, which impose a great burden on patients, both physically and mentally. Inspired by the high levels of reactive oxygen species (ROS) at the site of influenza A virus (IAV) infection, we have developed an intelligent responsive virus-mimicking nanodrug (Zana@HA-Lip) based on a biomimetic approach, reduces the damage of the drug to normal tissues or organs while achieving the purpose of antiviral therapy by precisely releasing the drug at the lesion site. Zana@HA-Lip offers distinct advantages regarding lesion site tropism, duration of action, and efficiency of release in response to ROS. This work not only presents a safe and effective strategy for alleviating lung injury caused by IAV infection but also introduces a new concept for the precise customization of virus-mimicking nanocarriers.

Following the national dynamic zero-COVID strategy adjustment, the utilization of broad-spectrum nasal neutralizing antibodies may offer an alternative approach to controlling the outbreak of Omicron variants between late 2022 and early 2023 in China. This study involved an investigator-initiated trial (IIT) to assess the pharmacokinetic, safety and efficacy of the F61 nasal spray. A total of 2,008 participants were randomly assigned to receive F61 nasal spray (24 mg/0.8 mL/dose) or normal saline (0.8 mL/dose) and 1336 completed the follow-up in the IIT. Minimal absorption of F61 antibody into the bloodstream was detected in individuals receiving F61 nasal spray for seven consecutive days. No treatment-emergent adverse reactions of grade 3 severity or higher were reported. In the one-dose cohort, the 7-day cumulative SARS-CoV-2 infection rate was 79.0% in the F61 group and 82.6% in the placebo group, whereas, in the multiple-dose (once daily for 7 consecutive days) cohort, the rates were 6.55% in the F61 group and 23.83% in the placebo group. The laboratory-confirmed efficacy of F61 was 3.78% (-3.74%-10.75%) in the one-dose cohort and 72.19% (57.33%-81.87%) in the multiple-dose cohort. In the real-world study, 60,225 volunteers in four different regions were administered the F61 nasal spray based on the subject's wishes, over 90% efficacy rate was observed against different Omicron variants. The F61 nasal spray, with its favourable safety profile, could be a promising prophylactic monoclonal antibody against SARS-CoV-2 VOCs.

为了寻求SARS-CoV-2 IgM抗体阳性血清质控品的替代品,本研究成功表达纯化出抗SARS-CoV-2 S蛋白IgM单克隆抗体.研究确定了 IgM单克隆抗体最佳表达载体为含增强子sp163和信号肽2的组合以及第5d为目的蛋白收获的最佳时间.此外在研究J链的作用时发现转染细胞时不添加J链(nCoV-163-IgM3)的表达量明显高于添加J链(nCoV-163-IgM3 J)时的表达量,J链对蛋白稳定性也无明显影响,且nCoV-163-IgM3和nCoV-163-IgM3 J抗原结合活性之间的差别无统计学意义(P＞0.05),nCoV-163-IgM3和nCoV-163-1gM3 J对本研究所检测的WT-S1、Alpha-S1、Beta-S1、Delta-S1、Omicron-S1、BA.2-S1、BF.7-RBD、XBB.1-S1、BQ1.1-S1 等九种抗原均有结合活性,只有一株(BA.2.75-RBD)逃逸.纯化后的目的蛋白经还原剂(β-ME)还原后显示重链分子量大小为70kD左右,轻链分子量大小为25kD左右.目的蛋白均可与新型冠状病毒抗体检测试剂盒(胶体金,INNOVITA)、SARS-CoV-2 S蛋白IgM抗体酶联免疫吸附测定试剂盒(Elabscience)、抗SARS-CoV-2 S-RBD蛋白人IgM抗体酶联免疫吸附测定试剂盒(Proteintech)等三种试剂盒反应.

由呼吸道病毒引起的疾病严重威胁着人类的生命健康,为了建立一种快速高通量的呼吸道病毒核酸检测方法,本研究将多重PCR技术同液相芯片技术结合起来,针对呼吸道合胞病毒A型和B型、乙型流感病毒Victoria系和Yamagata系、甲型流感病毒H1型和H3型以及新冠病毒等常见的七种呼吸道病毒,初步建立了七重呼吸道病毒液相芯片核酸检测技术,评价了方法的特异性、敏感性和重复性,并使用来自安徽省疾控的25份临床急性期样本核酸对方法进行验证.结果显示,建立起的基于液相芯片多重核酸检测方法可特异性识别七种目标呼吸道病毒的靶基因序列,与包括副流感病毒在内的9种非目标呼吸道病毒无交叉反应.对七种病毒核酸进行十倍稀释液相检测,其中H3、BV、RSVB可以检出 102拷贝/μL,BY、RSVA和SARS-CoV-2可以检出 103拷贝/μL,对H1的检测限为104拷贝/μL.25份样本核酸检测结果与实际相符.结果表明,本研究建立的七重呼吸道病毒液相芯片核酸检测技术具有特异性强、敏感性高、稳定性好等特点,可用于临床样本的快速检测,为呼吸道类传染病的液相芯片诊断奠定了实验室基础.

Multiple new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have constantly emerged, as the delta and omicron variants, which have developed resistance to currently gained neutralizing antibodies. This highlights a critical need to discover new therapeutic agents to overcome the variants mutations. Despite the availability of vaccines against coronavirus disease 2019 (COVID-19), the use of broadly neutralizing antibodies has been considered as an alternative way for the prevention or treatment of SARS-CoV-2 variants infection. Here, we show that the nasal delivery of two previously characterized broadly neutralizing antibodies (F61 and H121) protected K18-hACE2 mice against lethal challenge with SARS-CoV-2 variants. The broadly protective efficacy of the F61 or F61/F121 cocktail antibodies was evaluated by lethal challenge with the wild strain (WIV04) and multiple variants, including beta (B.1.351), delta (B.1.617.2), and omicron (B.1.1.529) at 200 or 1000 TCID50, and the minimum antibody administration doses (5-1.25 mg/kg body weight) were also evaluated with delta and omicron challenge. Fully prophylactic protections were found in all challenged groups with both F61 and F61/H121 combination at the administration dose of 20 mg/kg body weight, and corresponding mice lung viral RNA showed negative, with almost all alveolar septa and cavities remaining normal. Furthermore, low-dose antibody treatment induced significant prophylactic protection against lethal challenge with delta and omicron variants, whereas the F61/H121 combination showed excellent results against omicron infection. Our findings indicated the potential use of broadly neutralizing monoclonal antibodies as prophylactic and therapeutic agent for protection of current emerged SARS-CoV-2 variants infection.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs), especially the latest Omicron, have exhibited severe antibody evasion. Broadly neutralizing antibodies with high potency against Omicron are urgently needed for understanding the working mechanisms and developing therapeutic agents. In this study, we characterized the previously reported F61, which was isolated from convalescent patients infected with prototype SARS-CoV-2, as a broadly neutralizing antibody against all VOCs including Omicron BA.1, BA.1.1, BA.2, BA.3 and BA.4 sublineages by utilizing antigen binding and cell infection assays. We also identified and characterized another broadly neutralizing antibody D2 with epitope distinct from that of F61. More importantly, we showed that a combination of F61 with D2 exhibited synergy in neutralization and protecting mice from SARS-CoV-2 Delta and Omicron BA.1 variants. Cryo-Electron Microscopy (Cryo-EM) structures of the spike-F61 and spike-D2 binary complexes revealed the distinct epitopes of F61 and D2 at atomic level and the structural basis for neutralization. Cryo-EM structure of the Omicron-spike-F61-D2 ternary complex provides further structural insights into the synergy between F61 and D2. These results collectively indicated F61 and F61-D2 cocktail as promising therapeutic antibodies for combating SARS-CoV-2 variants including diverse Omicron sublineages.

Objective:To establish a simple, rapid and low-cost 2019 novel coronavirus (2019-nCoV) neutralizing antibody detection method.Methods:The 2019-nCoV RBD specific immunoglobulin G (RBD-IgG) detection method was established based on the principle of quantum dot immunochromatography(QDs), and the detection was evaluated by using of sera from coronavirus disease 2019 (COVID-19) convalescent patients ( N = 97), vaccinated donors ( N = 82) and healthy donors ( N = 299). The suitability of fingertip blood was evaluated by matching blood samples with peripheral blood ( N=54). Results:The 2019-nCoV RBD-IgG detection method based on QDs was successfully established. The detection result of QDSs had strong correlation ( Spearman r > 0.73, P < 0.000 1) and good consistency ( Kappa=0.93, P < 0.01) with the result of micro-neutralization test(MNT). The sensitivity and specificity were 92% and 99%, respectively. There was high correlation ( Spearman r =0.932 6, P < 0.000 1) and no significant difference ( P=0.102 6) between result of fingertip blood and peripheral blood. Fingertip blood can be used as a surrogate sample for testing. Conclusions:The 2019-nCoV neutralizing antibody detection method established in this study can provide an immediate, efficient and low-cost method selection for the assessment of herd immunity status, and provide technical support for the herd immunity monitoring of 2019-nCoV vaccinated population and the prevention and control of the epidemic.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has precipitated multiple variants resistant to therapeutic antibodies.In this study,12 high-affinity antibodies were generated from convalescent donors in early outbreaks using immune antibody phage display libraries.Of them,two RBD-binding antibodies (F61 and H121) showed high-affinity neutralization against SARS-CoV-2,whereas three S2-target antibodies failed to neutralize SARS-CoV-2.Following structure analysis,F61 identified a linear epitope located in residues G446-S494,which overlapped with angiotensin-converting enzyme 2 (ACE2) binding sites,while H121 recognized a conformational epitope located on the side face of RBD,outside from ACE2 binding domain.Hence the cocktail of the two antibodies achieved better performance of neutralization to SARS-CoV-2.Importantly,these two antibodies also showed efficient neutralizing activities to the variants including B.1.1.7 and B.1.351,and reacted with mutations of N501Y,E484K,and L452R,indicated that it may also neutralize the recent India endemic strain B.1.617.The unchanged binding activity of F61 and H121 to RBD with multiple mutations revealed a broad neutralizing activity against variants,which mitigated the risk of viral escape.Our findings revealed the therapeutic basis of cocktail antibodies against constantly emerging SARS-CoV-2 variants and provided promising candidate antibodies to clinical treatment of COVID-19 patients infected with broad SARS-CoV-2 variants.

The development of rapid serological detection methods re urgently needed for determination of neutralizing antibodies in sera. In this study, four rapid methods (ACE2-RBD inhibition assay, S1-IgG detection, RBD-IgG detection, and N-IgG detection) were established and evaluated based on chemiluminescence technology. For the first time, a broadly neutralizing antibody with high affinity was used as a standard for the quantitative detection of SARS-CoV-2 specific neutralizing antibodies in human sera. Sera from COVID-19 convalescent patients (N = 119), vaccinated donors (N = 86), and healthy donors (N = 299) confirmed by microneutralization test (MNT) were used to evaluate the above methods. The result showed that the ACE2-RBD inhibition assay calculated with either ACE2-RBD binding inhibition percentage rate or ACE2-RBD inhibiting antibody concentration were strongly correlated with MNT (r ≥ 0.78, p < 0.0001) and also highly consistent with MNT (Kappa Value ≥ 0.94, p < 0.01). There was also a strong correlation between the two evaluation indices (r ≥ 0.99, p < 0.0001). Meanwhile, S1-IgG and RBD-IgG quantitative detection were also significantly correlated with MNT (r ≥ 0.73, p < 0.0001), and both methods were highly correlated with each other (r ≥ 0.95, p < 0.0001). However, the concentration of N-IgG antibodies showed a lower correlation with the MNT results (r < 0.49, p < 0.0001). The diagnostic assays presented here could be used for the evaluation of SARS-CoV-2 vaccine immunization effect and serological diagnosis of COVID-19 patients, and could also have guiding significance for establishing other rapid serological methods to surrogate neutralization tests for SARS-CoV-2.

High rate of cardiovascular disease (CVD) has been reported among patients with coronavirus disease 2019 (COVID-19). Importantly, CVD, as one of the comorbidities, could also increase the risks of the severity of COVID-19. Here we identified phospholipase A2 group VII (PLA2G7), a well-studied CVD biomarker, as a hub gene in COVID-19 though an integrated hypothesis-free genomic analysis on nasal swabs (n=486) from patients with COVID-19. PLA2G7 was further found to be predominantly expressed by proinflammatory macrophages in lungs emerging with progression of COVID-19. In the validation stage, RNA level of PLA2G7 was identified in nasal swabs from both COVID-19 and pneumonia patients, other than health individuals. The positive rate of PLA2G7 were correlated with not only viral loads but also severity of pneumonia in non-COVID-19 patients. Serum protein levels of PLA2G7 were found to be elevated and beyond the normal limit in COVID-19 patients, especially among those re-positive patients. We identified and validated PLA2G7, a biomarker for CVD, was abnormally enhanced in COVID-19 at both nucleotide and protein aspects. These findings provided indications into the prevalence of cardiovascular involvements seen in patients with COVID-19. PLA2G7 could be a potential prognostic and therapeutic target in COVID-19.

Objective:To explore an early, rapid and accurate detection method of severe acute respiratory syndrome coronavirus 2 (2019-nCoV) antigen and improve the detection rate of patients with 2019-nCoV.Methods:We detected the characteristics of monoclonal antibodies (mAbs) against 2019-nCoV generated previously and established a double antibody sandwich ELISA against S protein of the virus.Results:All 12 mAbs against 2019-nCoV screened in our previous study were able to recognize purified virion and S protein. They were good candidates for detecting antibody to 2019-nCoV antigen. A double antibody sandwich ELISA established in this study could rapidly and effectively detect 2019-nCoV S protein with high sensitivity. The detection limit of 2019-nCoV S protein was lower than 1 ng/ml.Conclusions:This method could specifically detect 2019-nCoV antigen, and provided a meaningful reference for early, sensitive and specific diagnosis of COVID-19 infection.

Hantavirus disease is a globally distributed, natural foci-related infectious disease caused by hantavirus, that maintaining persistent infections in their rodent hosts without apparent disease symptoms but seriously affecting the health safety of human beings. Development of the disease depends on the interaction between virus, rodent host and the individual person. Factors as significant geographical and seasonal variations, certain periodicity and contingency can all be related to the incidence of hantavirus disease. The disease is affected by climate and meteorological,environment, economic and social development, human life style and individual behaviors, etc.. Results from the analysis on main influencing factors and the nature of epidemics provide as with more evidence and information in setting up programs onto timely implementation of related prevention and control measures scientifically. By searching relevant scientific and technological literature, this paper summarizes the factors that affecting the nature of transmission and infection of hantavirus from related perspectives and factors including virus, host, climate and meteorological, meteorology, geographical environment, economic and social factors, etc.. In order to elaborate on the understanding of the epidemics and transmission characteristics of this kind of diseases, this paper provides evidence on prediction, prevention and control measures of hantavirus disease.

What is already known on this topic?Hemorrhagic fever with renal syndrome (HFRS) is endemic in Liaoning Province. Both Seoul and Hantaan virus are circulating in rodents, and epidemic outbreaks and sporadic cases have been recorded every year since the disease was recognized.What is added by this report?The epidemic trend of HFRS over the past 20 years (1999-2018) in Liaoning was analyzed, which showed both regional complexity and consistence with the epidemic in China. Genetic and antigenic stability of the circulating hantavirus were demonstrated, which suggested the effectiveness of the approved inactivated vaccine currently used in China.What are the implications for public health practice?Precise risk-based strategic practices that are integrated and regional are required for further improvement of the prevention and control of HFRS.

拉沙热主要流行于西非,经鼠传播,人群普遍易感,病死率高,暴发疫情频发,跨境传播时有发生.拉沙病毒易于传播,病毒分离、培养需在生物安全四级实验室(BSL-4).2018年,世界卫生组织将其列为年度重点关注传染病,需加快研制防治关键技术手段.随着中非关系的日益紧密,贸易往来频繁,中国面临拉沙热的威胁显著增加.本文检索20世纪50年代首例拉沙热病例报道以来公开发表的主要文献,归纳拉沙热临床表现、病原学特征、流行病学特征、实验室检测以及跨境传播风险等,并对GenBank发布的全部287条拉沙病毒S基因编码区全长序列进行复核分析,以加强人们对拉沙热的了解,提高防控意识.

致病性汉坦病毒的宿主主要为啮齿类动物,其病毒感染状况是人间疫情发生的关键影响因素,可通过检测宿主动物标本中病毒基因组RNA、蛋白抗原及特异性抗体而进行监测.本研究利用367份鼠肺及鼠血标本,对双抗原夹心ELISA (ELISA)、实时荧光RT-PCR(RT-PCR)和免疫荧光(IFA)等三种分别检测抗体、核酸和抗原的方法进行比较评估.ELISA法检出抗体阳性鼠血标本46份,阳性率为12.53％;RT-PCR法检出病毒RNA阳性鼠肺标本28份,阳性率为7.63％;IFA检出抗原阳性鼠肺标本24份,阳性率为6.54％.宿主动物组织标本中检出汉坦病毒RNA和(或)结构蛋白抗原的标本,对应的血液标本中可检出病毒特异性抗体,100％ (24/24)IFA检测阳性标本和89.3％ (25/28) RT-PCR检测阳性标本对应血标本ELISA抗体检测阳性,反之亦然,检出抗体的标本基本包含了可检出抗原和RNA的标本.RT-PCR与IFA检测结果差异无显著性(x2a=0.64,P＞0.05),一致性检验Kappa系数为0.71,一致性高(Z=13.66,P＜0.05),首先对血标本开展基于ELISA的特异性抗体检测,可显著缩小RT-PCR或IFA法检测病毒RNA或抗原的范围(x2b=12.04,x2c=20.05,P＜0.05).本研究为宿主动物汉坦病毒感染实验室监测方案优化提供了有益的依据.

Objective To establish a fluorescent bead-based multiplex assay for the simultaneous detection of seven viral diseases endemic in Africa.Methods The genomic sequences of the viral pathogens causing Rift valley fever,Yellow fever,Marburg virus disease,Ebola virus disease,Lassa fever,CrimeanCongo hemorrhagic fever and Chikungunya fever were compared,PCR detection target fragments were selected,and amplification primers and hybrid probes were designed.The reference samples of related pathogens were prepared by chemical synthesis of DNA and in vitro transcription RNA.The sensitivity and stability of the detection method were evaluated.The specificity was evaluated by testing 30 samples of suspected dengue fever,and hantavirus diseases,and 32 healthy human blood samples.Results The fluorescent bead-based multiplex assay could specifically detect the corresponding pathogen,the detection limit was at a range of 102-105 copies/ μl,the specificity was 100％,and the intra-assay coefficient of variation was below 12％,and the inter-assay coefficient of variation was below 15％.Conclusions A fluorescent bead-based multiplex PCR assay for the simultaneous detection of seven viral diseases endemic in Africa was established,which may provide a new choice for the screening of suspected infectious diseases.