Animals ; Cytokines ; physiology ; Humans ; Influenza A virus ; immunology ; Influenza B virus ; immunology ; Influenza Vaccines ; Influenza, Human ; immunology ; prevention & control ; Vaccines, DNA

Adult ; Antibodies, Viral ; blood ; immunology ; Cross Reactions ; Hemagglutinin Glycoproteins, Influenza Virus ; immunology ; Humans ; Influenza A Virus, H1N1 Subtype ; immunology ; Influenza A Virus, H3N2 Subtype ; immunology ; Influenza B virus ; immunology ; Influenza Vaccines ; immunology ; Orthomyxoviridae ; immunology ; Seasons ; Vaccination

In order to understand the prevalence and variation of influenza B viruses, the antigenic and genetic characteristics of influenza B viruses circulating in Mainland China during April, 2011 to March, 2012 were analyzed. The results showed the B Victoria lineage viruses were much more prevalent than B Yamagata lineage during this period, phylogenetic analysis showed vast majority of Victoria lineage viruses belong to genetic group 1, intra-clade reassortant between HA1 and NA gene was identified in a minor proportion of the viruses. 72.8% of the B/Victoria-lineage viruses were antigenically closely related to the vaccine strain B/Brisbane/60/2008. B Yamagata component was not included in the trivalent influenza vaccine in China during the study period, however vast majority of B Yamagata lineage viruses were antigenically and genetically closely related to the representative virus B/Hubei-Wujiagang/158/2009(97.8%) and B/Sichuan-Anyue/139/2011(85.2%) in China, reassortant between HA1 and NA was not identified in B Yamagata lineage viruses. Overall, the predominant circulating influenza B viruses in 2011-2012 season in China were matched by current influenza vaccine and the selected representative viruses were proved to represent the antigenic and genetic characteristics of the circulating viruses.
China ; Humans ; Influenza B virus ; classification ; genetics ; immunology ; Influenza Vaccines ; genetics ; immunology ; Phylogeny ; Time Factors

<b>OBJECTIVEb>To analyse seasonal influenza epidemic situation in 2006, and to analyse the genetic and antigenic characteristics of viral hemagglutinin (HA) gene.

<b>METHODSb>The single-way hemagglutination inhibition (HI) tests were used to test the antigenic characteristics of these viruses from influenza surveillance network, and the HA1 genes were sequenced based on the antigenic test results according to different isolation times and sites.

<b>RESULTSb>The influenza virus types A and B co-circulated in 2006. influenza A H1N1 subtype and Victoria-like B influenza circulated preponderantly during this epidemic season. The HA1 gene sequence of H1N1 viruses showed that 192, 193, 196, 198 positions (located at antigenic site B) have an amino acid substitute, compared with the last circulating strain A/Hubeihongshan/53/2005(H1N1). Two amino acid changes at 142 and 144 positions compared with A/Yunnan/1145/2005 (H3N2). There was no change in influenza B viruses either Victoria-like B or Yamagata-like B virus, i.e . antigenic characteristics is analogous to B/shenzhen/155/2005 and B/tianjin/144/2005, respectively.

<b>CONCLUSIONb>The H1N1 and H3N2 influenza viruses had changing antigenic and genetic characteristics in 2006. Influenza virus types B did not change in 2006.

Amino Acids ; analysis ; China ; Hemagglutination Inhibition Tests ; Hemagglutinin Glycoproteins, Influenza Virus ; chemistry ; genetics ; immunology ; Influenza A Virus, H1N1 Subtype ; immunology ; isolation & purification ; Influenza A Virus, H3N2 Subtype ; immunology ; isolation & purification ; Influenza B virus ; immunology ; isolation & purification ; Time Factors

<b>OBJECTIVEb>To elevate the immunological effect of subunit influenza vaccine in infants and aged people (over 60) using liposomal adjuvant in the context of its relatively low immunity and to investigate the relation between vaccine antigens and liposomal characteristics.

<b>METHODSb>Several formulations of liposomal subunit influenza vaccine were prepared. Their relevant characteristics were investigated to optimize the preparation method. Antisera obtained from immunizinged mice were used to evaluate the antibody titers of various samples by HI and ELISA.

<b>RESULTSb>Liposomal trivalent influenza vaccine prepared by film evaporation in combinedation with freeze-drying significantly increased its immunological effect in SPF Balb/c mice. Liposomal vaccine stimulated the antibody titer of H3N2, H1N1, and B much stronger than conventional influenza vaccine. As a result, liposomal vaccine (mean size: 4.5-5.5 microm, entrapment efficiency: 30%-40%) significantly increased the immunological effect of subunit influenza vaccine.

<b>CONCLUSIONb>The immune effect of liposomal vaccine depends on different antigens, and enhanced immunity is not positively correlated with the mean size of liposome or its entrapped efficiency.

Animals ; Influenza A Virus, H1N1 Subtype ; immunology ; Influenza A Virus, H3N2 Subtype ; immunology ; Influenza B virus ; immunology ; Influenza Vaccines ; administration & dosage ; immunology ; Liposomes ; Mice ; Mice, Inbred BALB C ; Orthomyxoviridae Infections ; prevention & control ; Specific Pathogen-Free Organisms ; Vaccines, Subunit ; administration & dosage ; immunology

Adolescent ; Adult ; Antibodies, Viral ; blood ; Female ; Hemagglutination Tests ; Humans ; Influenza A virus ; immunology ; Influenza B virus ; immunology ; Influenza Vaccines ; classification ; immunology ; Influenza, Human ; immunology ; prevention & control ; Male ; Middle Aged ; Safety

<b>Objective:b> To evaluate the immunogenicity of inactivated quadrivalent influenza vaccine (QIV) in adults aged 18-64 years, through a Meta-analysis. <b>Methods:b> Literature was retrieved by searching the Medline, Cochrane Library, Science Direct in the past decade. All the studies were under random control trial (RCT) and including data related to immunogenicity which involving sero-protection rate (SPR) and sero-conversion rate (SCR) of the QIV, versus inactivated trivalent influenza vaccine (TIV) in the population aged 18 to 64. Revman 5.3 software was employed to manipulate the pooled date of the included literature. <b>Result:b> A total of 8 studies for the SPR and SCR of the shared strains (two A lineage and one B lineage) were included. There appeared no significant differences in the response rates between the two vaccines. As for QIV versus TIV (B/Yamagata), the pooled RR of the SPR for B/Victoria was 1.28 (95%CI: 1.08-1.51, P<0.05), with the pooled RR of the SCR for B/Victoria as 1.94 (95%CI: 1.50-2.50, P<0.05). For QIV versus TIV (B/Victoria), the pooled RR of the SPR for B/Yamagata as 1.10 (95%CI: 1.02-1.18, P<0.05), and the pooled RR of SCR for B/Yamagata as 1.99 (95%CI: 1.34-2.97, P<0.05). <b>Conclusion:b> In the population aged 18-64 years, inactivated QIV was equivalently immunogenic against the shared three strains included in the activated TIV while a superior immunogenic effect was noticed in the vaccine strain which did not include the inactivated QIV.
Adolescent ; Adult ; Antibodies, Viral/blood* ; Drug-Related Side Effects and Adverse Reactions ; Hemagglutination Inhibition Tests ; Humans ; Influenza A virus/immunology* ; Influenza B virus/immunology* ; Influenza Vaccines/immunology* ; Influenza, Human/prevention & control* ; Middle Aged ; Vaccines, Inactivated/immunology* ; Young Adult

Antigens, Viral ; metabolism ; China ; epidemiology ; Humans ; Influenza B virus ; classification ; genetics ; immunology ; Phylogeny

<b>OBJECTIVEb>To investigate the antigen clearance time, time to symptom disappearance, and the association between them using immunofluorescence assay for dynamic monitoring of influenza virus antigen in children with influenza.

<b>METHODSb>A total of 1 063 children suspected of influenza who visited the Hunan People's Hospital from March to April, 2016 were enrolled. The influenza A/B virus antigen detection kit (immunofluorescence assay) was used for influenza virus antigen detection. The children with positive results were given oseltamivir as the antiviral therapy and were asked to re-examine influenza virus antigen at 5, 5-7, and 7 days after onset.

<b>RESULTSb>Of all children suspected of influenza, 560 (52.68%) had an influenza virus infection. A total of 215 children with influenza virus infection were followed up. The clearance rate of influenza virus antigen was 9.8% (21 cases) within 5 days after onset. The cumulative clearance rate of influenza virus antigen was 32.1% (69 cases) within 5-7 days, and 98.1% (211 cases) within 7-10 days after onset. Among these children, 6 children (2.8%) achieved the improvement in clinical symptoms within 3 days after onset. The cumulative rate of symptom improvement was 84.7% (182 cases) within 3-5 days after onset, and 100% achieved the improvement after 5 days of onset.

<b>CONCLUSIONSb>The time to improvement in symptoms after treatment is earlier than antigen clearance time. Almost all of the children achieve influenza virus antigen clearance 7-10 days after onset. Therefore, it is relatively safe for children to go back to school within 7-10 days after onset when symptoms disappear.

Antigens, Viral ; blood ; Child ; Child, Preschool ; Female ; Fluorescent Antibody Technique ; Humans ; Infant ; Influenza A virus ; immunology ; Influenza B virus ; immunology ; Male ; Time Factors

<b>OBJECTIVEb>To investigate the epidemiological features of influenza virus B (IVB) in the winter and the clinical features of pediatric pneumonia caused by IVB only.

<b>METHODSb>A retrospective study was performed on the clinical data of children with respiratory infection who received pathogen testing and therapy at Soochow University Affiliated Children's Hospital during the winters of 2008, 2009, 2010 and 2011.

<b>RESULTSb>The positive rates of influenza viruses A and B in the winters of 2008, 2009, and 2010 were 0.89%, 5.49%, and 6.24% respectively; the positive rate of influenza viruses A and B in the winter of 2011 was 8.72%, significantly higher than those in 2008-2010. The positive rates of IVB in the winters of 2008, 2009, and 2010 were 0%, 0%, and 0.21% respectively; the positive rate of IVB in the winter of 2011 was 5.36%, which was significantly higher than in the years 2008 to 2010. Pneumonia caused by IVB was confirmed in 94 children during the winter of 2011, including 27 cases of pneumonia caused by IVB only. Most of children with pneumonia caused by IVB only were aged over 6 months. The common symptoms in the 27 children caused by IVB only were fever (85%), runny nose (89%), and cough (100%). Wheezing (26%) and dyspnea (7%) were also seen in some cases. Among the 27 children, 19% showed abnormal white blood cell count, 30% showed increased C-reactive protein, 70% showed decreased prealbumin, and none showed visible organ dysfunction. No specific imaging findings were seen in the children with pneumonia caused by IVB only. However, many abnormal humoral and cellular immunological parameters were found in the majority of these children. The average length of hospital stay was approximately one week, there were no critical patients and the prognosis was good.

<b>CONCLUSIONSb>Influenza viruses were at a peak level in inpatient children in the winter of 2011. IVB infection rate was gradually increasing. In children with pneumonia caused by IVB only, there are few critical patients, the symptoms are nonspecific and the prognosis is good.

Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Infant, Newborn ; Influenza B virus ; Influenza, Human ; diagnosis ; epidemiology ; immunology ; Length of Stay ; Male ; Pneumonia, Viral ; diagnosis ; epidemiology ; immunology ; Retrospective Studies