Assessing the Effect of Global Travel and Contact Restrictions on Mitigating the COVID-19 Pandemic

Travel restrictions and physical distancing have been implemented across the world to mitigate the coronavirus disease 2019(COVID-19)pandemic,but studies are needed to understand their effectiveness across regions and time.Based on the population mobility metrics derived from mobile phone geolocation data across 135 countries or territories during the first wave of the pandemic in 2020,we built a metapopulation epidemiological model to measure the effect of travel and contact restrictions on containing COVID-19 outbreaks across regions.We found that if these interventions had not been deployed,the cumulative number of cases could have shown a 97-fold(interquartile range 79–116)increase,as of May 31,2020.However,their effectiveness depended upon the timing,duration,and intensity of the interventions,with variations in case severity seen across populations,regions,and seasons.Additionally,before effective vaccines are widely available and herd immunity is achieved,our results emphasize that a certain degree of physical distancing at the relaxation of the intervention stage will likely be needed to avoid rapid resurgences and subsequent lockdowns.

Polymorphisms of the Vitamin D Receptor Gene and SexDifferential Associations with Lipid Profiles in Chinese Han Adults

Objective To explore the association of single nucleotide polymorphisms(SNPs)of the vitamin D receptor gene(VDR)with circulating lipids considering gender differences.Methods Of the Han Chinese adults recruited from a health examination center for inclusion in the study,the circulating lipids,25-hydroxyvitamin D(25OHD),and other parameters were measured.The VDR SNPs of Cdx2(rs11568820),Fok1(rs2228570),Apa1(rs7975232),and Taq1(rs731236)were genotyped with a qPCR test using blood DNA samples,and their associations with lipids were analyzed using logistic regression.Results In the female participants(n=236 with dyslipidemia and 888 without dyslipidemia),multiple genotype models of Fok1 indicated a positive correlation of B(not A)alleles with LDLC level(P<0.05).In the male participants(n=299 with dyslipidemia and 564 without dyslipidemia),the recessive model of Cdx2 and the additive and recessive models of Fok1 differed(P<0.05)between the HDLC-classified subgroups,respectively,and Fok1 BB and Cdx2 TT presented interactions with 25OHD in the negative associations with HDLC(P<0.05).Conclusion In the Chinese Han adults included in the study,the Fok1 B-allele of VDR was associated with higher LDLC in females,and the Fok1 B-allele and the Cdx2 T-allele of VDR were associated with lower HDLC in males.The interaction of VD and Fok1 BB or Cdx2 TT in males synergistically decreased HDLC levels.

Public Health Control Measures for the Co-circulation of Influenza and SARS-CoV-2 During Influenza Seasons

SEASONAL INFLUENZA IN THE MIDST OF COVID-19 The World Health Organization(WHO)named the disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)as coronavirus disease 2019(COVID-19)and declared the outbreak a Public Health Emergency of International Concern(PHEIC)on January 30,2020 and a pandemic on March 11,2020.Globally,there have been 239,437,517 confirmed cases of COVID-19 reported to WHO,including 4,879,235(2.1%)deaths as of October 15,2021(1).The COVID-19 pandemic continues to cause an unparalleled impact on global public health security and economic well-being in the context of previous influenza pandemics as well as other emerging infectious diseases in history(2).As the epidemiology,clinical presentations,and control measures for SARS-CoV-2 and influenza share many features,there is a need to develop strategies to address additional challenges arising in the continued surveillance,prevention,and clinical management of influenza in conjunction with COVID-19 pandemic responses.

How Shenzhen, China avoided widespread community transmission: a potential model for successful prevention and control of COVID-19

Shenzhen is a city of 22 million people in south China that serves as a financial and trade center for East Asia.The city has extensive ties to Hubei Province,the first reported epicenter of the coronavirus disease 2019(COVID-19)outbreak in the world.Initial predictions suggested Shenzhen would experience a high number of COVID-19 cases.These predictions have not materialized.As of 31 March 2020 Shenzhen had only 451 confirmed cases of COVID-19.Contact tracing has shown that no cases were the result of community transmission within the city.While Shenzhen did not implement a citywide lockdown like Wuhan,it did put into place a rapid response system first developed after the severe acute respiratory syndrome(SARS)epidemic in 2003.In the wake of the 2003 SARS outbreak,Shenzhen health authority created a network for surveillance and responding to novel respiratory infections,including pneumonia of unknown causes(PUC).The network rapidly detected mass discussion about PUC and immediately deployed emergency preparedness,quarantine for close contacts of PUC.Five early actions(early detection,early reporting,early diagnosis,early isolation,and early treatment)and four centralized responses(centralized coordination by experts,centralized allocation of resources,centralized placement of patients,and centralized provision of treatment)ensured effective prevention and control.Tripartite working teams comprising community cadres,medical personnel and police were formulated to conduct contact tracing at each neighborhood and residential community.Incorporation of mobile technology,big data,and artificial intelligence into COVID-19 response increased accessibility to health services,reduced misinformation and minimized the impact of fake news.Shenzhen’s unique experience in successfully controlling the COVID-19 outbreak may be a useful model for countries and regions currently experiencing rapid spread of the virus.

Interferon-induced Transmembrane Protein 3 Prevents Acute Influenza Pathogenesis in Mice

Objective Interferon-induced transmembrane protein 3(IFITM3)is an important member of the IFITM family.However,the molecular mechanisms underlying its antiviral action have not been completely elucidated.Recent studies on IFITM3,particularly those focused on innate antiviral defense mechanisms,have shown that IFITM3 affects the body’s adaptive immune response.The aim of this study was to determine the contribution of IFITM3 proteins to immune control of influenza infection in vivo.Methods We performed proteomics,flow cytometry,and immunohistochemistry analysis and used bioinformatics tools to systematically compare and analyze the differences in natural killer(NK)cell numbers,their activation,and their immune function in the lungs of Ifitm3-/-and wild-type mice.Results Ifitm3-/-mice developed more severe inflammation and apoptotic responses compared to wild-type mice.Moreover,the NK cell activation was higher in the lungs of Ifitm3-/-mice during acute influenza infection.Conclusions Based on our results,we speculate that the NK cells are more readily activated in the absence of IFITM3,increasing mortality in Ifitm3-/-mice.

Increased urbanization reduced the efectiveness of school closures on seasonal infuenza epidemics in China

Background:School closure is a common mitigation strategy during severe infuenza epidemics and pandemics.However,the efectiveness of this strategy remains controversial.In this study,we aimed to explore the efectiveness of school closure on seasonal infuenza epidemics in provincial-level administrative divisions(PLADs)with varying urbanization rates in China.Methods:This study analyzed infuenza surveillance data between 2010 and 2019 provided by the Chinese National Infuenza Center.Taking into consideration the climate,this study included a region with 3 adjacent PLADs in Northern China and another region with 4 adjacent PLADs in Southern China.The efect of school closure on infuenza transmission was evaluated by the reduction of the efective reproductive number of seasonal infuenza during school winter breaks compared with that before school winter breaks.An age-structured Susceptible-Infected-Recovered-Susceptible(SIRS)model was built to model infuenza transmission in diferent levels of urbanization.Parameters were determined using the surveillance data via robust Bayesian method.Results:Between 2010 and 2019,in the less urbanized provinces:Hebei,Zhejiang,Jiangsu and Anhui,during school winter breaks,the efective reproductive number of seasonal infuenza epidemics reduced 14.6%[95%confdential interval(CI):6.2–22.9%],9.6%(95%CI:2.5–16.6%),7.3%(95%CI:0.1–14.4%)and 8.2%(95%CI:1.1–15.3%)respectively.However,in the highly urbanized cities:Beijing,Tianjin and Shanghai,it reduced only 5.2%(95%CI:-0.7–11.2%),4.1%(95%CI:-0.9–9.1%)and 3.9%(95%CI:-1.6–9.4%)respectively.In China,urbanization is associated with decreased proportion of children and increased social contact.According to the SIRS model,both factors could reduce the impact of school closure on seasonal infuenza epidemics,and the proportion of children in the population is thought to be the dominant infuencing factor.Conclusions:Efectiveness of school closure on the epidemics varies with the age structure in the population and social contact patterns.School closure should be recommended in the low urbanized regions in China in the infuenza seasons.

Repeat HIV Testing and Incident Rates among Individuals Attending Voluntary Counseling and Testing Clinics in Wuxi, China： A Retrospective Study

Objective We aimed to elucidate the rates of repeat HIV testing and incident HIV diagnosis, and baseline CD4^＋ T cell count among individuals attending HIV voluntary counseling and testing （VCT） clinics in Wuxi, China. Methods A repeat HIV testing within 12 months was recorded if individuals had their first test with negative results, during 2013-2014 and retested within 12 months. An incident HIV diagnosis was recorded if individuals had their first test with negative results, during 2013-2015 and had a subsequent positive result at any point by the end of 2015. Data on HIV testing and diagnosis among individuals attending 32 VCT clinics from 2013 to 2015 and HIV diagnosis from other clinical services in Wuxi, China, were retrieved. A multivariate logistic regression model was used to analyze factors associated with repeat HIV testing. Cox regression was used to evaluate factors associated with incident HIV diagnosis. Results From 2013 to 2014, 11,504 individuals tested HIV negative at their first recorded test, with 655 （5.7%） retesting within 12 months. Higher repeat HIV testing within 12 months was associated with male gender [adjusted odds ratio （a OR） = 1.7, 95% confidence interval （CI）： 1.4-2.2], risk behaviors [commercial heterosexual behaviors （a OR = 1.4, CI： 1.1-1.6）, male-male sexual behaviors （a OR = 3.7, CI： 2.7-4.9）], injection drug use （a OR = 9.9, CI： 6.5-15.1）, and having taken HIV tests previously （a OR = 2.0, CI： 1.6-2.4）. From 2013 to 2015, 1,088 individuals tested negative on HIV test at their visit and at ≥ 2 subsequent tests; of them 30 had incident HIV diagnosis. The overall rate of incident HIV diagnosis among all VCT individuals was 1.6 （95% CI： 1.1-2.1） per 100 person-years. Incident HIV diagnosis was associated with male gender [adjusted hazard ratio （a HR） = 8.5, 95% CI： 1.9-38.1], attending hospital-based VCT clinics （a HR = 7.8, 95% CI： 1.1-58.3）, and male-male sexual behavior （a HR = 8.4, 95% CI： 1.5-46.7）. Individuals diagnosed at VCT clinics had higher CD4＋ T cell count compared with those diagnosed at other clinical services （median 407 vs. 326 copies/mm3, P = 0.003）. Conclusion VCT individuals in Wuxi, China, had a low repeat HIV testing rate and high HIV incidence. VCT-clinic-based interventions aimed at increasing repeat HIV testing are needed to detect more cases at an earlier stage, especially among individuals at high risk for HIV infection such as men who have sex with men.

Characterization of time-and size-dependent particle emissions and decay from cooking oil fumes in residence:Impacts of various intervention measures

The dynamic characteristics of cooking-related particle size distributions in real-world settings are not fully understood.Through a real-world campaign in a naturally-ventilated apartment in the northwest US,this study investigates the temporal profiles of size-resolved particle number concentrations(PNCs)ranging from 0.3 to 10µm from frying cooking activities.The cooking scenarios included various combinations of window ventilation,venting range hood(VRH)use,and portable air cleaner(PAC)utilization.Following a standardized pan-frying protocol throughout seven scenarios,real-time PNCs of 16-size bins were measured in the kitchen.The PNCs were empirically compared among size bins,periods,and scenarios.The most abundant size ranges of cooking-related particles were 0.3–0.579µm in number(45%–71%of the total)and 2.685–5.182µm in mass(48%–57%of the total).Compared with the scenario without any cooking-fume mitigating measures,keeping the kitchen windows open reduced the mean PNCs during and within 1-h after cooking for PM_(0.3-2.5),PM_(2.5-10),and PM_(0.3-10)by 78%,92%,and 79%,respectively.By contrast,utilizing a VRH during cooking reduced the corresponding levels by 21%,69%,and 25%,respectively.Combined with running the VRH,using a PAC in the kitchen led to additional reductions of 84%,88%,and 84%,respectively.Additionally,the removal efficiencies of the three strategies generally increased with particle sizes.

Correlates of Sexual Lifestyles Among Older Adults Living With HIV in China: Findings From the Sexual Well-being (SWELL) Study

Sexual lifestyles are closely related to overall human health and well-being.Few studies have focused on sexual lifestyles among older adults living with HIV(OALHIV),especially in low-and middle-income countries.This study is a part of the sexual well-being among older adults in China(SWELL)study,which is a multicenter cross-sectional study focused on sexual health among older adults aged 50 years and older.Participants were 680 OALHIV(≥50 years old)from the SWELL study conducted from June 2020 to December 2022.Data were collected through one-on-one interviews.We used logistic regression to assess the correlates of sexual activity and sexual satis-faction.Among all participants,37.1%were sexually active.Being older,male,in a steady relationship and employed were associated with being sexually active.The prevalence of sexual satisfaction was 69.8%among sexually active OALHIV.Being homosexual and reporting a better general health status were associated with sexual satisfaction.The OALHIV who have depressive symptoms were less likely to report sexual satisfaction.To support holistic healthy aging among OALHIV,it is important for healthcare providers to be educated about the importance of enquiring about sexual activity,satisfaction and problems and addressing concerns while conveying sex-positive attitudes during clinical reviews,as these are still critical aspects of their health and well-being.

Placental transfer of bisphenol diglycidyl ethers (BDGEs) and its association with maternal health in a population in South of China

Despite high production and usage,little is known about exposure to bisphenol diglycidyl ethers(BDGEs)and their derivatives in pregnant women and fetuses.In this study,we determined nine BDGEs in 106 paired maternal and cord serum samples collected from e-waste dismantling sites in South of China.Bisphenol A bis(2,3-dihydroxypropyl)glycidyl ether(BADGE⋅2H_(2)O),bisphenol A(3-chloro-2-hydroxypropyl)(2,3-dihydroxypropyl)glycidyl ether(BADGE⋅HCl⋅H_(2)O),and bisphenol F diglycidyl ether(BFDGE)were the major BDGEs,with median concentrations of 0.57,4.07,and 1.60 ng/mL,respectively,in maternal serum,and of 3.58,5.61,and 0.61 ng/mL,respectively,in cord serum.The transplacental transfer efficiencies(TTEs)were estimated for BDGEs found in samples,and median values were in the range of 0.98(BFDGE)to 5.91(BADGE⋅2H_(2)O).Our results suggested that passive diffusion plays a role in the placental transfer of BADGE⋅HCl⋅H_(2)O and BFDGE,whereas several mechanisms contribute to the high accumulation of BADGE⋅2H_(2)O in cord serum.Multiple linear regression analysis indicated significant associations between maternal serum concentrations of BDGEs and blood clinical biomarkers,especially those related to liver injuries,such as alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),and adenosine deaminase(ADA)(P<0.05).To our knowledge,this is the first study to report the occurrence of BDGEs in paired maternal–fetal serum samples and provide new insights into prenatal and fetal exposures.The newly discovered TTEs in maternal–fetal pairs contribute to a fuller inventory of the transmission activity of pollutants in the human body,ultimately adding to a more significant comprehensive risk evaluation.

Safety and Immunogenicity of SARS-CoV-2 Vaccines in People Living With HIV:A Systematic Review and Meta-analysis of Real-World Studies

The safety and immunogenicity of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)vaccines in people living with HIV(PLWH)in real-world studies remain controversial.Thus,we conducted a comprehensive systematic review and meta-analysis to address this issue.Data search were conducted from PubMed,Web of Science and EMBASE.Adverse events following vaccination,the risk ratio(RR)of SARS-CoV-2–specific IgG seroconversion and the level of anti–SARS-CoV-2 neutralizing antibodies were compared between the PLWH group and a healthy control group.A total of 10,582 PLWH from 22 studies were included.In our analysis,the incidence of local or systemic adverse events after the first SARS-CoV-2 vaccine dose was not statistically different between PLWH and healthy controls.However,there was a statistical difference after the second dose(RR,0.83;95%CI,0.71–0.98).The seroconversion rate of SARS-CoV-2 IgGantibodies in PLWH was significantly lower than that in the healthy control group(RR,0.94;95%CI,0.89–0.98;I2=80%,P<0.01).The anti–SARS-CoV-2 neutralizing antibody titers in PLWH after full immunization were also significantly lower than those in the healthy control group(RR,0.91;95%CI,0.85–0.98;I2=81%,P<0.01).The safety and tolerance of COVID-19 vaccines in PLWHare acceptable.However,their immunogenicitymay be impaired to a certain extent,characterized by a lower IgGseroconversion rate and neutralizing antibody titers compared with healthy individuals.These findings should provide guidance for optimizing future COVID-19 vaccination strategies among PLWH.

The protective nasal boosting of a triple-RBD subunit vaccine against SARS-CoV-2 following inactivated virus vaccination

Dear Editor,Though COVID-19 vaccines have been developed and clinically deployed rapidly,new variants of concern(VOCs)are still emerging frequently and escalating around the world.More breakthrough infections occurred even vaccination rates are high.For possible ending of the pandemic,curbing infection and stopping transmission are priority.

B cell engineering in vivo:Accelerating induction of broadly neutralizing antibodies against HIV-1 infection

In a recent study published in Nature Biotechnology,1 Nahmad and colleagues reported in vivo B-cell engineering to generate broadly neutralizing antibodies(bnAbs)against human immunodeficiency virus type 1(HIV-1)in mice.This proof-of-concept study suggests the possibility of in vivo B-cell engineering as a novel preventive or therapeutic approach against HIV-1 infection.

First clinical study of germline-targeting strategy: One step closer to a successful bnAb-based HIV vaccine

The epidemic of human immunodeficiency virus type 1(HIV-1)remains amajor threat to global public health,with approximately 38 million people living with HIV-1 worldwide.However,a prophylactic vaccine against HIV-1 is not available yet.In a recent study,1 Leggat and colleagues reported the first-in-human test of a germline-targeting HIV-1 vaccine candidate,eOD-GT860-mer adjuvanted with AS01B.Encouragingly,this strategy effectively activated the B cell precursors(germlines)of VRC01-class broadly neutralizing antibodies(bnAbs)in 97%(35 of 36)of vaccine recipients.

Transmission risk of asymptomatic SARS-CoV-2 infection:a systematic review and meta-analysis

Background:Global evidence on the transmission of asymptomatic SARS-CoV-2 infection needs to be synthesized.Methods:A search of 4 electronic databases(PubMed,EMBASE,Cochrane Library,and Web of Science databases)as of January 24,2021 was performed.Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines were followed.Studies which reported the transmission rate among close contacts with asymptomatic SARS-CoV-2 cases were included,and transmission activities occurred were considered.The trans-mission rates were pooled by zero-inflated beta distribution.The risk ratios(RRs)were calculated using random-effects models.Results:Of 4923 records retrieved and reviewed,15 studies including 3917 close contacts with asymptomatic indexes were eligible.The pooled transmission rates were 1.79 per 100 person-days(or 1.79%,95%confidence interval[CI]0.41%-3.16%)by asymptomatic index,which is significantly lower than by presymptomatic(5.02%,95%CI 2.37%-7.66%;p<0.001),and by symptomatic(5.27%,95%CI 2.40%-8.15%;p<0.001).Subgroup anal-yses showed that the household transmission rate of asymptomatic index was(4.22%,95%CI 0.91%-7.52%),four times significantly higher than non-household transmission(1.03%,95%CI 0.73%-1.33%;p=0.03),and the asymptomatic transmission rate in China(1.82%,95%CI 0.11%-3.53%)was lower than in other countries(2.22%,95%CI 0.67%-3.77%;p=0.01).Conclusions:People with asymptomatic SARS-CoV-2 infection are at risk of transmitting the virus to their close contacts,particularly in household settings.The transmission potential of asymptomatic infection is lower than symptomatic and presymptomatic infections.This meta-analysis provides evidence for predict-ing the epidemic trend and promulgating vaccination and other control measures.Registered with PROS-PERO International Prospective Register of Systematic Reviews,CRD42021269446;https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=269446.

Acceptance and Factors Associated With Participation in Functional Cure–Related Trials Among People Living With HIV: A Cross-sectional Study in Southern China

HIV remains a global health challenge,and research efforts directed towards a functional cure require people living with HIV(PLHIV)in-volvement in clinical trials.Our study assessed willingness to participate in HIV functional cure–related clinical trials and associated fac-tors among PLHIV in Guangzhou,China,using a questionnaire survey approach.We analyzed responses from 718 questionnaires,finding that 71.2%were willing to participate in Phase Ⅲtrials,while 51.7%were willing to participate in Phase I trials and 42.9%expressed acceptability for analytic treatment interruption.Multivariate logistic regression demonstrated that male PLHIV,those with awareness of functional cure,and PLHIV,who had been on antiretroviral therapy(ART)for less than 1 year,were more willing to partic-ipate in Phase Ⅲtrials.Those with a body mass index greater than 24,and those without resistance to ART drug were more willing to participate in Phase I trials.The major motivations for participation in Phase Ⅲtrials were access to cutting-edge treatments(62.6%)and supporting research(55.3%).Safety was the main concern contributing to hesitancy.Our study revealed a high willingness to participate in HIV functional cure–related trials among PLHIV in Guangzhou,China,and willingness varied across different trial phases and was in-fluenced by multiple factors.This study provides valuable references for future clinical trial recruitment strategies and public health policy formulation.

Challenges and Strategies for Influenza Response After COVID-19 Pandemic

After the World Health Organization(WHO)declared the coronavirus disease 2019(COVID-19)pandemic in March 2020,the implementation of the most effective interventions became a paramount public health priority in the global response to the COVID-19 pandemic,especially before vaccines were available.Several studies have demonstrated that nonpharmaceutical interventions(NPIs),such as social distancing,wearing facemasks,and school closures,can substantially control the transmission of respiratory infections,including severe acute respiratory syndrome,pandemic H1N1 in 2009,and the COVID-19 pandemic.[1–3]However,various respiratory infections have become more prevalent since the COVID-19 pandemic.Since 2021,the incidence of respiratory syncytial virus(RSV)has rapidly increased in numerous countries,including the United States,[4]Australia,[5]England,[6]Italy,[7]Germany,[8]and Switzerland.[9]In December 2022,5 European countries,including France and the United Kingdom。

Building and sharing medical cohorts for research

Cohort studies are costly and time consuming.They require not only laboratory equipment and assays but also collaboration from participants and health agencies.Due to cost constraints,they are often confined to a specific population.Nevertheless,they play a crucial role in providing fundamental insights for medical advancements,shedding light on the origins of diseases,and acting in socioeconomic influence in policy making.

A triple-RBD-based mucosal vaccine provides broad protectionagainst SARS-CoV-2 variants of concern

The rapid mutation and spread of SARS-CoV-2 variants urge the development of effective mucosal vaccines to provide broadspectrum protection against the initial infection and thereby curb the transmission potential.Here,we designed a chimeric tripleRBD immunogen,3Ro-NC,harboring one Delta RBD and two Omicron RBDs within a novel protein scaffold.3Ro-NC elicits potent and broad RBD-specific neutralizing immunity against SARS-CoV-2 variants of concern.Notably,intranasal immunization with 3RoNC plus the mucosal adjuvant KFD(3Ro-NC+KFDi.n)elicits coordinated mucosal IgA and higher neutralizing antibody specificity(closer antigenic distance)against the Omicron variant.In Omicron-challenged human ACE2 transgenic mice,3Ro-NC+KFDi.n immunization significantly reduces the tissue pathology in the lung and lowers the viral RNA copy numbers in both the lung(85.7-fold)and the nasal turbinate(13.6-fold).Nasal virologic control is highly correlated with RBD-specific secretory IgA antibodies.Our data show that 3Ro-NC plus KFD is a promising mucosal vaccine candidate for protection against SARS-CoV-2 Omicron infection,pathology and transmission potential.

Epidemiology and Genotypic Diversity of Eurasian Avian-Like H1N1 Swine Influenza Viruses in China

Eurasian avian-like H1 N1(EA H1 N1)swine influenza virus(SIV)outside European countries was first detected in Hong Kong Special Administrative Region(Hong Kong,SAR)of China in 2001.Afterwards,EA H1 N1 SIVs have become predominant in pig population in this country.However,the epidemiology and genotypic diversity of EA H1 N1 SIVs in China are still unknown.Here,we collected the EA H1 N1 SIVs sequences from China between 2001 and 2018 and analyzed the epidemic and phylogenic features,and key molecular markers of these EA H1 N1 SIVs.Our results showed that EA H1 N1 SIVs distributed in nineteen provinces/municipalities of China.After a long-time evolution and transmission,EA H1 N1 SIVs were continuously reassorted with other co-circulated influenza viruses,including 2009 pandemic H1 N1(A(H1 N1)pdm09),and triple reassortment H1 N2(TR H1 N2)influenza viruses,generated 11 genotypes.Genotype 3 and 5,both of which were the reassortments among EA H1 N1,A(H1 N1)pdm09 and TR H1 N2 viruses with different origins of M genes,have become predominant in pig population.Furthermore,key molecular signatures were identified in EA H1 N1 SIVs.Our study has drawn a genotypic diversity image of EA H1 N1 viruses,and could help to evaluate the potential risk of EA H1 N1 for pandemic preparedness and response.