Human parainfluenza virus (HPIV) is important respiratory pathogen that could cause bronchitis and pneumonia in infants, young children and other immunocompromised populations. At present, there are no vaccines or drugs approved for specific prevention and treatment of HPIV infection. In this review we introduce the development of HPIV vaccines from five categories including inactivated vaccine, live attenuated vaccine, subunit vaccine, mRNA vaccine and combined vaccine.

Objective To analyze the antigenicity,genetic characteristics and variation of the hemagglutinin(HA) protein of influenza A(H1N1)pdm09 virus circulating in Shanghai during 2018-2019 influenza surveillance year.Methods Hemagglutinin inhibition test was performed to analyze the antigenicity of eighty-four influenza A(H1N1)pdm09 virus strains isolated in Shanghai from April 2018 to March 2019.Sixty-five influenza virus strains isolated from different districts of Shanghai were sequenced and analyzed.Results Clade 6B.1 H1N1 virus was the predominant strains circulating in Shanghai.A few epidemic strains belong to the 6B.2 branch.The similarities of clade 6B.1 nucleotide sequences compared with the vaccine strain A/Michigan/45/2015 were 97.1％-98.8％.The homology with the newly recommended vaccine strain A/Brisbane/02/2018 were 97.5％-99.4％.Mainly fifteen amino acids had mutated in the HA protein sequence,and three mutations,S91R,S181T and T202I were involved in three different epitopes which indicated that the antigenic drift had occurred in the influenza virus.Conclusions The majority of influenza A(H1 N 1)pdm09 subtype virus strains circulating in Shanghai were well matched with the vaccine strain A/Michigan/45/2015 recommended by WHO.It is necessary to continue strengthening the surveillance on influenza virus variation to improve the efficacy of influenza vaccines.

ObjectiveTo determine the genomic characteristics of a subgenus B human adenovirus strain isolated in Shanghai in 2021. MethodsAn adenovirus type 55 strain was isolated and identified from a patient with acute hemorrhagic conjunctivitis （AHC）. Complete genome of the strain was obtained using the next-generation sequencing （NGS）. Phylogenetic trees were reconstructed based on the sequences of Hexon， Fiber， Penton and complete genome to genomically characterize this strain. ResultsPhylogenetic analysis based on the complete genome classified this strain （MH2021001） into subgenus B， subspecies B2 of HAdV-55. Hexon gene of MH2021001 had close phylogenetic relationship with HAdV-11， while Fiber and Penton genes had close relationship with HAdV-14. The MH2021001 showed high nucleotide identity with currently prevalent HAdV⁃55 strains （>99.90%）. The complete genome had 99.96% nucleotide identity to the 73-GD_CHN_2016 strain isolated in Guangdong. In addition， the amino acid sequence of MH2021001 had several substitutions in regions coding for E1B， L4， E3 and L5. ConclusionThis strain has been classified to HAdV-B55. No recombination event is identified in the complete genome. Due to multiple amino acid substitutions， the biological characteristics of the strain need to be further identified.

ObjectiveTo isolate and study the biological characteristics of severe acute respiratory syndrome coronavirus 2 （SARS-CoV-2） from feces of coronavirus disease 2019 （COVID-19） patients. MethodsVero E6 cells were used for virus isolation and the isolated strains were tested by nucleic acid test， immunofluorescence test， virulence test and whole genome sequencing. 50% tissue culture infective dose （TCID₅₀） was calculated after the cell cultures of each generation were collected ResultsEight fecal specimens were inoculated with Vero E6 cells after treatment and cultured for 48 h. One specimen showed obvious cytopathic effect on Vero E6 cells. One SARS-CoV-2 out of 8 fecal samples from COVID-19 patients were isolated， and separation rate was 12.5%. The TCID₅₀ of P1， P2 and P3 were 10^4.0/0.2 mL， 10^4.5/0.2 mL and 10^4.75/0.2 mL， respectively. Only one of the 8 stool samples had SARS-CoV-2 virus replication and amplification， and the Ct value of the nucleic acid detection was about 10. The sequence of the isolation was more than 99.99% homologous with that of Wuhan-Hu-1（GenBank MN908947）. ConclusionThe SARS-CoV-2 strain is isolated from the fecal samples of COVID-19 cases and is confirmed by genomic sequencing and immunofluorescence test， which indicates the presence of live virus in feces of COVID-19 cases.

ObjectiveTo understand the whole genome characteristics and the information for genetic evolution in the two coxsackievirus A2 (CVA2) strains isolated from patients with herpangina in Shanghai, and to provide a scientific basis for the prevention and treatment of herpetic angina. MethodsTwo CAV2 strains isolated from patients with herpetic angina in Shanghai were performed whole genome sequencing and analysis for phylogenetics, nucleotide homology, and evolution. ResultsA phylogenetic analysis of the VP1 region revealed that the two Shanghai strains both belonged to CVA2 genotype D, with the highest homology to OL357660, a strain from Yunnan. The average nucleotide identity (ANI) of the whole genome between the two Shanghai strains was 98.88%, and the ANI of the whole genome comparisons to other CVA2 genotype D strains and CVA2 genotypes A-C strains ranged from 84.64% to 97.42% and from 79.21% to 84.20%, respectively. The two Shanghai strains had low homology in the 3D region compared to the existing CVA2 strains. The phylogenetic analysis and sliding window nucleotide similarity analysis indicated that the two Shanghai strains and the Yunnan OL357660 strain might constitute a new genetic lineage. ConclusionThe two CVA2 strains isolated for the first time in Shanghai are assigned to genotype D (GenBank: PQ130039 and PQ130040), which is identical to the existing subtype prevalent in China. As represented by the Shanghai strains, a new CVA2 genetic lineage is been identified. This study has enriched the data on genetic evolution and genetic variation of CVA2 in Shanghai, indicating the requirement to strengthen surveillance for the epidemiological pattern of CVA2.