This study investigated the full-genome molecular characteristics of a rotavirus vaccine-derived strain,G1P[8]geno-type A group rotavirus RVA/Human-wt/CHN/HN1140/2021/G1P[8](referred to as HN1140).The gene fragments of the HN1140 strain were amplified with reverse transcription-polymerase chain reaction(RT-PCR)combined with whole-genome primers to obtain the full genome sequence.Genotyping was performed with the online genotyping tool RotaC 2.0,and similarity and genetic evolution analyses for each gene segment were conducted in DNAstar5.1 and MEGA11.0 software.The genotype of the HN1140 strain was deter-mined to be G1-P[8]-I2-R2-C2-M2-A3-N2-T6-E2-H3.Phylogenetic analysis demonstrated that all 11 genomic segments clus-tered closely with the RotaTeq vaccine strains,sharing 99.7%-100%nucleotide sequence similarity.Notably,VP1,VP2,VP6,and NSP2-NSP5 segments showed 100%nucleotide identity with RotaTeq strains.Comparative genomic analysis identified 13 nucleotide and 8 amino acid substitutions between HN1140 and RotaTeq strains,localized within the VP7,VP4,VP1,VP2,VP3,and NSP1 segments.The HN1140 strain exhibited the genotype G1-P[8]-A3-T6-H3,which was consistent with the typical profile of a vaccine-derived reassortant.This strain demonstrated high genetic similarity to RotaTeq vaccine strains,with nucleotide sequence identity ranging from 99.7%to 100%.These findings suggested that HN1140 evolved from RotaTeq vaccine strains through genetic reassortment.

Objective:To understand the molecular evolutionary characteristics of the recombinant strain GII.3[P12] of norovirus acute gastroenteritis outbreaks and aggregated outbreaks in China from 2022 to 2023.Methods:Epidemiological information, case information, clinical samples, as well as detection and genotyping information of norovirus outbreaks and aggregated outbreaks from 2022 to 2023 were collected; positive samples of the GII.3[P12] recombinant strain were subjected to nucleic acid extraction, whole-genome amplification, and sequence analysis; and homology simulation method were used to construct a three-dimensional structure and predict antigenic epitopes.Results:From January 2022 to December 2023, a total of 1 136 norovirus outbreaks and aggregated outbreaks were reported in China′s norovirus outbreak surveillance network, and genotyping result were successfully obtained for 942 outbreaks, with GII dominating, accounting for 76.0% (716/942), and the proportion of GI and mixed genotypes being 15.8% (149/942) and 8.2% (77/942). Norovirus outbreaks caused by GII were dominated by GII.3[P12] (22.5%, 161/716), while other major genotypes included GII.17[P17] (18.7%, 134/716), GII.4_Sydney 2012[P16] (11.6%, 83/716) and GII.6[P7] ( 11.3%, 81/716). 2022-2023 Outbreaks caused by GII.3[P12] were concentrated in February-March (54.0%, 87/161), with the main outbreaks occurring in nursery and primary schools (87.5%), the mode of transmission was mainly human-to-human (68.9%), and the main susceptible population was children aged 3-7 years (93.3%). In this study, the genome sequences of 25 GII.3[P12] recombinant strains were obtained, and according to the phylogenetic analysis, it was shown that the GII.3[P12] recombinant strains in China in 2022-2023 belonged to the Cluster IV cluster of sublineage b (7 strains) and sublineage c (18 strains). A total of 11 linear and 8 conformational epitopes were predicted by epitope prediction analysis, and the predicted linear and conformational epitopes had overlapping positions, and each conformational epitope was part of the predicted linear epitope with conserved potential antigen-binding and receptor-binding sites.Conclusions:The recombinant strain GII.3[P12] is one of the epidemic strains that will cause outbreaks and clusters of norovirus in China in 2022-2023, and its genome did not undergo significant mutation.

Group C rotavirus（RVC）is one of the important etiological agents responsible for human rotavirus gastroenteritis（RVGE）. Although its overall detection rate has shown a declining trend in recent years，sporadic outbreaks continue to be reported，highlighting its potential public health threat. RVC infections predominantly occur in preschool children，adolescents，and adults，typically presenting with mild to moderate diarrhea. While most cases are sporadic，cluster outbreaks can also occur. At present，fundamental research on RVC remains limited，particularly regarding its transmission and pathogenesis. Nevertheless，emerging evidence suggests that interspecies transmission may represent a key route of human infection. This review provides a comprehensive overview of current research on RVC-associated gastroenteritis，with a particular focus on its virological characteristics，epidemiological patterns，clinical manifestations，and preventive and control strategies. It aims to offer a theoretical foundation and practical reference for future studies and public health interventions targeting RVC.

This study investigated the immunogenicity of type 5 replication deficient recombinant adenovirus comprising the fused receptor binding domain protein(RBD)and capsid protein(N)of the SARS-CoV-2 Omicron strain.The overlap PCR method was used to obtain the RBDgs3N fragment.The plasmid pKAd5ES-RBDgs3N was obtained through homologous recombination,and re-combinant virus was amplifiedand harvested after transfection of HEK293 cells.Cesium chloride density gradient centrifugation was used to purify the recombinant adenovirus,and the viral titer was determined through limited dilution analysis.The fusion protein ex-pression was identified with the western blot(WB)method.Recombinant adenovirus was injected intramuscularly into BALB/c mice,and the specific immune responses of the mice were detected with indirect ELISA and enzyme-linked immunosorbent spot technology.The titer of the recombinant adenovirus pKAd5ES-RBDgs3N virus seed was 1.168×1010 IU/mL.The RBDgs3N fusion protein was suc-cessfully expressed in HEK293 cells.Single dose intramuscular immunization significantly induced production of IgG antibodies against wild type(WT)SARS-CoV-2 virus and variant(Delta and Omicron)RBDs in mice,with antibody titers of 103.677 8,103.878 5,and 104.454 9,respectively.The specific antibody titer against N protein was 104.942 2.The level of IFN-γ secretion for RBD specific cellu-lar immunity was 1 452 SFC/106 cells.The type 5 replication deficient recombinant adenovirus with RBD and N gene fusion constructed in this study elicited high levels of specific antibodies against RBD and N protein and RBD specific cellular immunity in BALB/c mice,thus providing a basis for further evaluation of the recombinant adenovirus as a potential SARS-CoV-2 vaccine.

This study investigated the full-genome molecular characteristics of a rotavirus vaccine-derived strain,G1P[8]geno-type A group rotavirus RVA/Human-wt/CHN/HN1140/2021/G1P[8](referred to as HN1140).The gene fragments of the HN1140 strain were amplified with reverse transcription-polymerase chain reaction(RT-PCR)combined with whole-genome primers to obtain the full genome sequence.Genotyping was performed with the online genotyping tool RotaC 2.0,and similarity and genetic evolution analyses for each gene segment were conducted in DNAstar5.1 and MEGA11.0 software.The genotype of the HN1140 strain was deter-mined to be G1-P[8]-I2-R2-C2-M2-A3-N2-T6-E2-H3.Phylogenetic analysis demonstrated that all 11 genomic segments clus-tered closely with the RotaTeq vaccine strains,sharing 99.7%-100%nucleotide sequence similarity.Notably,VP1,VP2,VP6,and NSP2-NSP5 segments showed 100%nucleotide identity with RotaTeq strains.Comparative genomic analysis identified 13 nucleotide and 8 amino acid substitutions between HN1140 and RotaTeq strains,localized within the VP7,VP4,VP1,VP2,VP3,and NSP1 segments.The HN1140 strain exhibited the genotype G1-P[8]-A3-T6-H3,which was consistent with the typical profile of a vaccine-derived reassortant.This strain demonstrated high genetic similarity to RotaTeq vaccine strains,with nucleotide sequence identity ranging from 99.7%to 100%.These findings suggested that HN1140 evolved from RotaTeq vaccine strains through genetic reassortment.

This study investigated the immunogenicity of type 5 replication deficient recombinant adenovirus comprising the fused receptor binding domain protein(RBD)and capsid protein(N)of the SARS-CoV-2 Omicron strain.The overlap PCR method was used to obtain the RBDgs3N fragment.The plasmid pKAd5ES-RBDgs3N was obtained through homologous recombination,and re-combinant virus was amplifiedand harvested after transfection of HEK293 cells.Cesium chloride density gradient centrifugation was used to purify the recombinant adenovirus,and the viral titer was determined through limited dilution analysis.The fusion protein ex-pression was identified with the western blot(WB)method.Recombinant adenovirus was injected intramuscularly into BALB/c mice,and the specific immune responses of the mice were detected with indirect ELISA and enzyme-linked immunosorbent spot technology.The titer of the recombinant adenovirus pKAd5ES-RBDgs3N virus seed was 1.168×1010 IU/mL.The RBDgs3N fusion protein was suc-cessfully expressed in HEK293 cells.Single dose intramuscular immunization significantly induced production of IgG antibodies against wild type(WT)SARS-CoV-2 virus and variant(Delta and Omicron)RBDs in mice,with antibody titers of 103.677 8,103.878 5,and 104.454 9,respectively.The specific antibody titer against N protein was 104.942 2.The level of IFN-γ secretion for RBD specific cellu-lar immunity was 1 452 SFC/106 cells.The type 5 replication deficient recombinant adenovirus with RBD and N gene fusion constructed in this study elicited high levels of specific antibodies against RBD and N protein and RBD specific cellular immunity in BALB/c mice,thus providing a basis for further evaluation of the recombinant adenovirus as a potential SARS-CoV-2 vaccine.

Objective:To understand the molecular evolutionary characteristics of the recombinant strain GII.3[P12] of norovirus acute gastroenteritis outbreaks and aggregated outbreaks in China from 2022 to 2023.Methods:Epidemiological information, case information, clinical samples, as well as detection and genotyping information of norovirus outbreaks and aggregated outbreaks from 2022 to 2023 were collected; positive samples of the GII.3[P12] recombinant strain were subjected to nucleic acid extraction, whole-genome amplification, and sequence analysis; and homology simulation method were used to construct a three-dimensional structure and predict antigenic epitopes.Results:From January 2022 to December 2023, a total of 1 136 norovirus outbreaks and aggregated outbreaks were reported in China′s norovirus outbreak surveillance network, and genotyping result were successfully obtained for 942 outbreaks, with GII dominating, accounting for 76.0% (716/942), and the proportion of GI and mixed genotypes being 15.8% (149/942) and 8.2% (77/942). Norovirus outbreaks caused by GII were dominated by GII.3[P12] (22.5%, 161/716), while other major genotypes included GII.17[P17] (18.7%, 134/716), GII.4_Sydney 2012[P16] (11.6%, 83/716) and GII.6[P7] ( 11.3%, 81/716). 2022-2023 Outbreaks caused by GII.3[P12] were concentrated in February-March (54.0%, 87/161), with the main outbreaks occurring in nursery and primary schools (87.5%), the mode of transmission was mainly human-to-human (68.9%), and the main susceptible population was children aged 3-7 years (93.3%). In this study, the genome sequences of 25 GII.3[P12] recombinant strains were obtained, and according to the phylogenetic analysis, it was shown that the GII.3[P12] recombinant strains in China in 2022-2023 belonged to the Cluster IV cluster of sublineage b (7 strains) and sublineage c (18 strains). A total of 11 linear and 8 conformational epitopes were predicted by epitope prediction analysis, and the predicted linear and conformational epitopes had overlapping positions, and each conformational epitope was part of the predicted linear epitope with conserved potential antigen-binding and receptor-binding sites.Conclusions:The recombinant strain GII.3[P12] is one of the epidemic strains that will cause outbreaks and clusters of norovirus in China in 2022-2023, and its genome did not undergo significant mutation.

Group C rotavirus（RVC）is one of the important etiological agents responsible for human rotavirus gastroenteritis（RVGE）. Although its overall detection rate has shown a declining trend in recent years，sporadic outbreaks continue to be reported，highlighting its potential public health threat. RVC infections predominantly occur in preschool children，adolescents，and adults，typically presenting with mild to moderate diarrhea. While most cases are sporadic，cluster outbreaks can also occur. At present，fundamental research on RVC remains limited，particularly regarding its transmission and pathogenesis. Nevertheless，emerging evidence suggests that interspecies transmission may represent a key route of human infection. This review provides a comprehensive overview of current research on RVC-associated gastroenteritis，with a particular focus on its virological characteristics，epidemiological patterns，clinical manifestations，and preventive and control strategies. It aims to offer a theoretical foundation and practical reference for future studies and public health interventions targeting RVC.

Objective:To analyze the genetic stability of two recombinant rotaviruses (rLLR/NSP3 NLuc) and (rLLR/NSP3 CoV2/RBD) that are inserted and express exogenous genes for continuous passage and proliferation on MA104 cells.Methods:After measuring the titers of two recombinant rotavirus strains, they were transferred to the P2 generation according to MOI0.01. Subsequently, the previous generation of virus lysate was diluted and activated at 1∶100, and MA104 cells were continuously infected for 18 generations (P20). The virus titers of the P1, P5, P10, P15, and P20 generation of cell lysate were measured using indirect immunofluorescence, and RT-PCR identification and dsRNA PAGE silver staining were performed. The luciferase activity of rLLR/NSP3-NLUc was also detected.Results:No inserted fragment loss was found in the recombinant rotavirus rLLR/NSP3 NLuc within 20 generations, with recombinant virus titers ranging from 3.85~5.16 × 10 6 FFU/ml, with strong luciferase signals in each generation. The recombinant rotavirus rLLR/NSP3 CoV2/RBD showed loss of inserted fragments in the 6th generation, with infectivity titers ranging from 2.6 to 3.36 in the first 5 generations of the recombinant virus × 10 6 FFU/ml. Conclusions:The recombinant rotavirus with 582 bp NLuc inserted at the end of the NSP3 gene has good genetic stability, while the recombinant rotavirus with 885 bp RBD inserted at the end of the NSP3 gene was only stable in the first 5 generations, indicating that foreign genes can be inserted at the end of the NSP3 gene of the recombinant rotavirus, and the insert can express, but its stability requires more in-depth research.

Objective:To analyze the epidemiological characteristics of norovirus (NoV) acute gastroenteritis (AGE) outbreaks caused by GII.17[P17] variant in China, 2022.Methods:Information and specimens of AGE outbreaks between January and December 2022 were collected. NoV RNA was detected in all specimens by real-time RT-PCR. The viral genome of the positive specimens were amplified, sequenced and analyzed.Results:Between January and December 2022, 360 AGE outbreaks were reported cumulatively, of which 266 outbreaks successfully obtained genotype results. GII.17 [P17] was one of the main genotypes and detected in 34 outbreaks (12.78%, 34/266), with the highest number of outbreaks detected in spring (6 outbreaks in March and 7 outbreaks in May), mainly in childcare facilities and primary schools (61.76%, 21/34). According to the result of NoV genotype analysis in different age groups, 14 strains of GII.17 [P17] in this study belonged to Cluster III b and SC III branch of Cluster III (Kawasaki308) in the capsid region and polymerase region, respectively, and both belonged to the same cluster as the variant strain (GZ41621 strain) that caused the NoV AGE outbreaks in China during the 2014/15 season. Compared to reference strains of Cluster I, Cluster II and Cluster III a, Cluster III b was provided with 22 amino acid mutations in VP1. The main amino acid changes in the subgroup of Cluster III b including the virus strains isolated in this study were at T294I and Q299R of antigen epitope A, an insertion mutation occurred at antigen epitope D, H353Q at the site I of the human histo-blood group antigen receptor binding site. The selection pressure analysis detected a large number of negative selection sites, indicating that negative selection plays an important role in the evolution of VP1 genes.Conclusions:GII.17 [P17] was one of the primary genotypes responsible for NoV diarrhea outbreaks in China in 2022. Phylogenetic analysis had revealed that it still belonged to the same cluster as the novel GII.17 [P17] variant (strain GZ41621) that caused NoV epidemics in China during the 2014/15 season, exhibiting minor amino acid variations at the potential epitope.