Child ; Humans ; Respiratory Syncytial Virus Infections ; immunology ; virology ; Respiratory Syncytial Virus, Human ; immunology ; pathogenicity

Humans ; Molecular Epidemiology ; Respiratory Syncytial Virus Infections ; epidemiology ; virology ; Respiratory Syncytial Virus, Human ; genetics

Human Respiratory Syncytial Virus (HRSV) is a serious threat to the population health. The elderly are one of the susceptible populations. The prevalence of HRSV in the elderly is generally higher than that in other age groups except children, which has gradually attracted attention in recent years. This paper reviewed the prevalence, common complications and major complications of HRSV in the elderly, briefly expounded the economic burden of HRSV infection, and proposed that attention should be paid to the disease burden of the elderly after HRSV infection, timely treat common complications, so as to reduce the occurrence of adverse survival outcomes and provide scientific evidence for the prevention and control of HRSV infection in the elderly.
Child ; Humans ; Aged ; Respiratory Syncytial Virus Infections/epidemiology* ; Respiratory Syncytial Virus, Human

Human respiratory syncytial virus (HRSV) is one of the main pathogen causing severe acute lower respiratory tract infections in infants and the elderly, with high incidence rate and mortality worldwide. Vaccine is one of the important measure to prevent infection, transmission and severe disease of HRSV, but currently there is no officially approved preventive vaccine for prevention of HRSV in the world. This paper reviews and analyzes the current research and development progress of HRSV vaccine, summarizes the design routes of different types of HRSV preventive vaccines, and discusses the difficulties and challenges in vaccine research and development, in order to provide reference for the research and development of HRSV vaccine and the development of clinical trials.
Infant ; Humans ; Aged ; Respiratory Syncytial Virus, Human ; Respiratory Syncytial Virus Infections/epidemiology* ; Respiratory Syncytial Virus Vaccines/therapeutic use* ; Respiratory Tract Infections

OBJECTIVE: To find out the prevalence of respiratory syncytial virus (RSV) genotypes in southern Zhejiang Province, China, and to study the genetic characteristics of G protein from subtype A of RSV. METHODS: The lower respiratory tract secretions of children under 5 years of age who were hospitalized for pneumonia and bronchiolitis in three hospitals in southern Zhejiang Province from July 2009 to June 2014 were collected. Direct immunofluorescence assay was used to detect RSV antigens from the collected secretions. A total of 200 samples were randomly selected from RSV-positive specimens in each prevailing year (from July of a specific year to June of the next year). RT-PCR was used to determine RSV subtypes, and the near-full length gene sequence of G protein from subtype A was amplified and sequenced to identify the genotype. RESULTS: A total of 25 449 samples of lower respiratory tract secretions were collected from 2009 to 2014, among which 6 416 (25.21%) samples were RSV-positive. Among the 1 000 RSV-positive specimens randomly sampled, 462 strains (46.2%) were subtype A, and 538 strains (53.8%) were subtype B. Subtype A accounted for 22.5%, 74.5%, 84.5%, 19.0%, and 30.5% of the total strains in each year from 2009 to 2014. A total of 25 RSV subtype A strains were randomly sampled and sent out for bidirectional sequencing in each year, which confirmed 52 positive subtype A strains. Four genotypes of subtype A strains were obtained from the above strains, including NA1 (39 strains), NA4 (1 strain), ON1 (10 strains), and GA2 (2 strains). NA1 was the dominant genotype between 2009 and 2012, and ON1 was the only genotype of subtype A during 2013-2014. The nucleotide homology and amino acid homology between the G protein of subtype A and the prototype strain A2 were 80.7%-89.3% and 74.4%-82.6%, respectively. The nucleotide homology and amino acid homology between the isolates of subtype A were 81.5%-100% and 80.2%-100%, respectively. CONCLUSIONS In southern Zhejiang Province from 2009 to 2014, there was a co-circulation of RSV subtypes A and B, as well as a co-circulation of several different genotypes of RSV subtype A, which had highly variable G protein genes.
Child, Preschool ; China ; Epidemiologic Studies ; Genotype ; Humans ; Infant ; Infant, Newborn ; Phylogeny ; Respiratory Syncytial Virus Infections ; epidemiology ; Respiratory Syncytial Virus, Human

Human respiratory syncytial virus (HRSV) is a major cause of severe respiratory tract illnesses in infants and young children worldwide. Despite its importance as a respiratory pathogen, there is currently no licensed vaccine for HRSV. Following failure of the initial trial of formalin-inactivated virus particle vaccine, continuous efforts have been made for the development of safe and efficacious vaccines against HRSV. However, several obstacles persist that delay the development of HRSV vaccine, such as the immature immune system of newborn infants and the possible Th2-biased immune responses leading to subsequent vaccine-enhanced diseases. Many HRSV vaccine strategies are currently being developed and evaluated, including live-attenuated viruses, subunit-based, and vector-based candidates. In this review, the current HRSV vaccines are overviewed and the safety issues regarding asthma and vaccine-induced pathology are discussed.
Asthma ; Child ; Humans ; Immune System ; Infant ; Infant, Newborn ; Respiratory Syncytial Virus, Human ; Respiratory Syncytial Viruses ; Respiratory System ; Vaccines ; Virion

Laboratory diagnosis of respiratory viral infection has traditionally been based upon virus isolation and/or viral antigen identification. Recently, more sensitive and specific nucleic acid detection methods by reverse transcription- polymerase chain reaction (RT-PCR) have been developed, however, conventional RT-PCR can identify only a single suspected virus. To identify the causative agents which belong to Paramyxoviridae of respiratory virus infections, we have developed a single-tube multiplex RT-PCR using four primer sets which can amplify respiratory syncytial virus and parainfluenza virus type 1, 2 and 3 simultaneously. Assay sensitivity of single-tube multiplex RT-PCR allowed a detection in the range of 3~500 TCID50 and there were no cross amplification among other respiratory viral agents based on the test using reference virus stocks. The single-tube multiplex RT-PCR was able to directly detect viruses in respiratory specimens, with virus being detected 11 of 80 samples as compared to 9 of 80 samples detected by indirect immunofluorescence or antigen detection following shell vial culture. This result suggests that the single-tube multiplex RT-PCR can be established as a more sensitive and rapid diagnostic application than shell vial assay for the detection of respiratory infection of Paramyxoviridae.
Clinical Laboratory Techniques ; Fluorescent Antibody Technique, Indirect ; Humans* ; Parainfluenza Virus 1, Human* ; Paramyxoviridae ; Paramyxoviridae Infections* ; Polymerase Chain Reaction* ; Respiratory Syncytial Virus, Human* ; Respiratory Syncytial Viruses ; Reverse Transcription*

Human Respiratory Syncytial virus (hRSV) is a leading cause of severe lower respiratory tract diseases in the pediatric population.hRSV frequently causes severe morbidity and mortality in high risk groups including infants with congenital heart disease and the immunosuppressed patients. Although hRSV is recognized as a major public health threat and economic burden worldwide, there is no licensed vaccine and effective therapeutic agent. Viral nonstructural (NS) proteins have been known to play multiple functions for efficient viral replication and pathogenesis. Especially, diverse functions of influenza A virus NS1 have been extensively studies. Recent studies demonstrated that NS1 and NS2 of RSV also exert diverse functions to modulate cellular environment and antiviral immune responses. Since NS proteins of RSV are required for efficient replication and pathogenesis, NS mutant viruses have been tested as live-attenuated vaccines. This review will outline the recent progress in understanding the various functions of RSV NS1 and NS2.
Heart Defects, Congenital ; Humans ; Infant ; Influenza A virus ; Interferons ; Mortality ; Public Health ; Respiratory Syncytial Virus, Human ; Respiratory Syncytial Viruses* ; Respiratory Tract Diseases ; Vaccines

OBJECTIVETo investigate the epidemiological characteristics of respiratory syncytial virus (RSV) subtypes and genotypes in southern Zhejiang province, and to determine whether RSV genotypes are correlated with the disease severity of lower respiratory tract infection (LRTI).

METHODNasopharyngeal secretions (NPS) from children under 5 years of age who were hospitalized with LRTI during 5 consecutive seasons from July 1, 2009 to June 30, 2014 were collected. RSV antigen was determined using direct immunofluorescence (DIF). Two hundred strains of RSV were randomly selected from each epidemic season. RNA was extracted and identified as subtype A or B by using reverse transcription-polymerase chain reaction (RT-PCR), and randomly selected strains of the full length attachment (G) genes of both subtype A and subtype B were amplified by PCR and sequencing. Clinical data were collected, and the disease severity between different genotypes were compared simultaneously.

RESULTOf the total 1 000 randomly selected RSV positive samples, 462 (46.2%) and 538 (53.8%) samples were identified as subtype A and B, respectively. It was found that subtype B predominated in the 2009-2010 and 2012-2014 epidemic seasons and subtype A in 2010-2012 epidemic seasons. A total of 112 strains of complete sequences of G genes were obtained, including four subtype A genotypes NA1, NA4, GA2 and ON1, and six subtype B genotypes BA8-10, BA-C, CB1, and GB2. Phylogenetic analysis revealed that 39/52 (75.0%) subtype A strains were classified as NA1 genotype, followed by ON1 genotype (10/52,19.2%) and 44/60 (73.3%) subtype B strains were classified as BA9 genotype, followed by BA8 genotype (6/60,10.0%). BA9 was the predominant genotype among subtype B except 2010-2011 epidemic season, while NA1 was the predominant genotype among subtype A except 2013-2014 epidemic season. Only ON1 and BA9 genotypes were checked out during 2013-2014 epidemic season. There was statistically significant difference in the average severity score of illness in 39 cases infected with NA1 genotype (4.154) and 44 cases of BA9 genotype (3.341) (U=642.500, P<0.05). Furthermore, in the rate of oxygen uptake, the percentage of those infected with NA1 genotype (33.3%) was higher than those infected with BA9 genotype (13.6%) (χ2=4.544, P<0.05). However, there were no significant difference in the age, clinical symptoms, the percentage of intensive care unit admission, length of hospitalization and the outcome of the disease between NA1 and BA9 infection.

CONCLUSIONThe shift of predominant RSV subtype from 2009 to 2014 were B-A-A-B-B in the southern areas of Zhejiang province. Multiple genotypes co-circulated during five RSV epidemic seasons. NA1 and BA9 genotypes were the predominant genotypes of subtype A and B, respectively. Compared with infection with BA9 genotype, NA1 genotype infection was associated with more severe disease and proportion of patients needed oxygen therapy was higher.

Child, Preschool ; China ; epidemiology ; Genotype ; Hospitalization ; Humans ; Infant ; Nasopharynx ; Phylogeny ; Polymerase Chain Reaction ; Respiratory Syncytial Virus Infections ; epidemiology ; Respiratory Syncytial Virus, Human ; genetics ; Respiratory Tract Infections ; epidemiology ; Seasons

Objective: To understand the detection rate, epidemic pattern of respiratory syncytial virus (RSV) in hospitalized children with acute lower respiratory tract infection (ALRTI) in China. Methods: From June 2017 to March 2020, a prospective multi-center study on the viral aetiology among hospitalized children with ALRTI was conducted in six pediatrics hospital of North China, Northeast, Northwest, South China, Southeast, and Southwest China. A total of 2 839 hospitalized children with ALRTI were enrolled, and the respiratory specimens were collected from these cases. A multiplex real-time RT-PCR assay were employed to screen the respiratory viruses, and the molecular epidemiological and clinical characteristics of children infected with RSV were analyzed. Results: The positve rate of RSV was 18.6% (528/2 839), and the positive rate of RSV in different regions ranged from 5.5% to 44.3%. The positive rate of RSV in male was higher than that in female (20.2% vs 16.3%), and there was a significant statistically difference between two groups (χ2=6.74, P=0.009). The positive rate of RSV among children under 5 years old was higher than that among children older than 5 years old (22.3% vs 4.5%), and there was a significant statistically difference between two groups (χ2=97.98,P<0.001). The positive rate of RSV among the <6 months age group was higher than that of other age groups (all P<0.05). During January 2018 and December 2019, RSV was detected in almost all through the year, and showed peaks in winter and spring. RSV-positive cases accounted for 17.0% (46/270) among children with severe pneumonia, including 36 cases infected with RSV alone. Conclusion: RSV is an important viral pathogen in children under 5 years old with ALRTI in China. The virus can be detected almost all through the year and reached the peak in winter and spring. RSV could lead to severe pneumonia in children and caused huge threaten to children's health.
Child ; Humans ; Male ; Female ; Infant ; Child, Preschool ; Respiratory Syncytial Virus Infections/epidemiology* ; Child, Hospitalized ; Prospective Studies ; Respiratory Tract Infections/epidemiology* ; Respiratory Syncytial Virus, Human ; China/epidemiology*