Abattoirs ; manpower ; Adult ; Antibodies, Viral ; blood ; China ; Humans ; Influenza A Virus, H1N1 Subtype ; immunology ; Influenza A Virus, H3N2 Subtype ; immunology ; Influenza A Virus, H3N8 Subtype ; immunology ; Influenza A Virus, H5N1 Subtype ; immunology ; Influenza A Virus, H9N2 Subtype ; immunology ; Influenza A virus ; classification ; immunology ; Influenza, Human ; epidemiology ; prevention & control ; virology ; Middle Aged ; Population Surveillance ; methods ; Seroepidemiologic Studies ; Young Adult

Animals ; Birds ; China ; epidemiology ; Humans ; Influenza A Virus, H5N1 Subtype ; physiology ; Influenza A Virus, H7N7 Subtype ; physiology ; Influenza A Virus, H9N2 Subtype ; physiology ; Influenza A virus ; physiology ; Influenza, Human ; epidemiology ; prevention & control

<b>INTRODUCTIONb>Since the emergence of the pandemic influenza A/H1N1/2009 virus in April 2009, diagnostic testing in many countries has revealed the rapid displacement and then replacement of circulating seasonal influenza viruses by this novel virus.

<b>MATERIALS AND METHODSb>In-house seasonal and pandemic influenza-specific polymerase chain reaction assays were introduced and/or developed at the Molecular Diagnosis Centre (MDC) at the National University Hospital (NUH), Singapore. These assays have been used to test all samples received from in-patients, out-patients, staff and visitors for suspected pandemic influenza A/H1N1/2009 infection.

<b>RESULTSb>Prior to the arrival of the pandemic A/H1N1/2009 virus in Singapore at the end of May 2009, seasonal influenza A/H3N2 predominated in this population, with very little seasonal influenza A/H1N1 and B viruses detected. Within about 1 month of its arrival in Singapore (mainly during June to July 2009), this pandemic virus rapidly displaced seasonal influenza A/H3N2 to become the predominant strain in the Singaporean population served by MDC/NUH.

<b>CONCLUSIONSb>Realtime molecular techniques have allowed the prompt detection of different influenza subtypes during this current pandemic, which has revealed the displacement/replacement of previously circulating seasonal subtypes with A/H1N1/2009. Although some of this may be explained by immunological cross-reactivity between influenza subtypes, more studies are required.

Communicable Diseases, Emerging ; Cross Reactions ; Disease Outbreaks ; Humans ; Influenza A Virus, H1N1 Subtype ; isolation & purification ; Influenza B virus ; isolation & purification ; Influenza, Human ; classification ; diagnosis ; epidemiology ; Influenzavirus C ; isolation & purification ; Molecular Diagnostic Techniques ; Polymerase Chain Reaction ; Singapore ; epidemiology

The expression of the hemagglutinins of Avian influenza virus H5 H7and H9 subtypes was studied in this article by Pichia pastoris, one of the eukaryotis expression systems. Three reconstructed expression plasmids and engineering strains, named pPIC9K-H5HA, pPIC9K-H7HA, pPIC9K-H9HA and GS115/pPIC9K-H5HA, GS115/pPIC9K-H7HA, GS115/pPIC9K-H9HA repectively, were obtained. The reconstructed yeast engineering strains were identified by MD and MM plate selecting and PCR. The induced interests proteins were examined by SDS-PAGE and Western-bloting,the results showed that the interest genes were expressed exactly. And this will be helpful in the future study of antigen detection and antibody detection kit, as well in the subunit vaccines developing.
Animals ; Hemagglutinin Glycoproteins, Influenza Virus ; biosynthesis ; genetics ; Influenza A Virus, H5N1 Subtype ; genetics ; Influenza A Virus, H7N7 Subtype ; genetics ; Influenza A Virus, H9N2 Subtype ; genetics ; Pichia ; genetics ; metabolism

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

Specific primers and TaqMan MGB probes were designed with Primer Express 2.0 software according to the conserved region of the H5, H9, H7 subtype AIV hemagglutinin gene to make research of real-time fluorescent one-step PCR in the differential detection of H5, H9, H7 subtype avian influenza inactivated vaccines. The result showed that the method was specific and reproducible. No cross-reaction was discovered with other avian disease vaccines. Real-time fluorescent PCR provided a specific, sensitive, rapid and convenient method for the subtype identification of avian influenza inactivated vaccines.
Animals ; Hemagglutinin Glycoproteins, Influenza Virus ; immunology ; Humans ; Influenza A Virus, H5N1 Subtype ; immunology ; Influenza A Virus, H7N7 Subtype ; immunology ; Influenza A Virus, H9N2 Subtype ; immunology ; Influenza A virus ; classification ; immunology ; Influenza Vaccines ; analysis ; classification ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Vaccines, Inactivated ; analysis

<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

To explore the impact of the history of infection by the influenza A virus subtype H1N1 on secondary infection by the influenza A virus subtype H9N2, pigs non-infected and pre-infected with H1N1 were inoculated with H9N2 in parallel to compare nasal shedding and seroconversion patterns. Unlike pigs without a background of H1N1 infection, nasal shedding was not detected in pigs pre-infected with H1N1. Both groups generated antibodies against H9N2. However, levels of H1N1 antibodies in pigs pre-infected with H1N1 increased quickly and dramatically after challenge with H9N2. Cross-reaction was not observed between H1N1 antibodies and H9N2 viruses. These findings suggest that circulation of the H1N1 virus might be a barrier to the introduction and transmission of the avian H9N2 virus, thereby delaying its adaptation in pigs.
Animals ; Antibodies, Viral ; immunology ; Cross Reactions ; Immune Sera ; immunology ; Influenza A Virus, H1N1 Subtype ; immunology ; physiology ; Influenza A Virus, H9N2 Subtype ; immunology ; Orthomyxoviridae Infections ; blood ; immunology ; Species Specificity ; Swine ; immunology ; virology

Ribavirin is a broad-spectrum inhibitor against several unrelated DNA or RNA viruses in vitro and in vivo. In this paper the in vitro and in vivo study of anti-influenza virus activity of ribavirin (RBV) injection had been reported. The in vitro antiviral activity of ribavirin injection against influenza virus A and B was studied by CPE. The in vivo protective action of ribavirin injection against influenza A/FM/1/47(H1N1) mouse adapted strain infected mouse was studied with mouse model. The results showed ribavirin injection has strong inhibitory activity against 7 virus strains tested in vitro. Ribavirin injection could significantly increase virus infected mouse survival rate and survival days and improve lung pathogen and lung index.
Animals ; Antiviral Agents ; administration & dosage ; pharmacology ; therapeutic use ; Cell Line ; Cytopathogenic Effect, Viral ; drug effects ; Dogs ; Female ; Influenza A Virus, H1N1 Subtype ; drug effects ; Influenza A Virus, H3N2 Subtype ; drug effects ; Influenza B virus ; drug effects ; Injections ; Lung ; pathology ; Mice ; Orthomyxoviridae Infections ; drug therapy ; pathology ; Ribavirin ; administration & dosage ; pharmacology ; therapeutic use

Phylogenetic studies of influenza A viruses have revealed species-specific lineages of viral genes, and that aquatic birds are the source of all influenza viruses in other animal species including humans, pigs, horses, sea mammals and birds. Influenza pandemics, defined as global outbreaks of the disease due to new antigenic subtypes, have exacted a high death toll from human populations. The most devastating pandemic, the so-called Spanish influenza of 1918 to 1919, resulted from an H1N1 virus and caused the deaths of at least 20 million people worldwide. Other much less catastrophic pandemics occurred in 1957 (Asian influenza [H2N2 virus]), 1968 (Hong Kong influenza [H3- N2 virus]), and 1977 (Russian influenza [H1N1 virus]). It is noteworthy that both the Asian and Hong Kong outbreaks were caused by hybrid viruses, or reassortants, that harbored a combination of avian and human viral genes. Avian influenza viruses are therefore key contributors to the emergence of human influenza pandemics. Fowl plague caused by highly pathogenic avian influenza A viruses is a constant threat to the poultry industry, but until the Hong Kong influenza outbreak, there was no zoonotic evidence that avian viruses could be transmitted directly to humans. In May 1997, an H5N1 influenza virus was isolated from a 3-year-old boy in Hong Kong, who died of extensive influenza pneumonia. By the end of 1997, a total of 18 cases of human influenza as an emerging infection had been identified, all caused by the same H5N1 virus. With this outbreak, it became clear that the virulence potential of these viruses extended to humans. The H5N1 isolates were not reassortants like the 1957 and 1968 pandemic strains; instead, all of the viral genes had originated from an avian virus. It will be critical to identify the molecular determinants that allow efficient transmission and replication of avian influenza viruses in humans, so that probable pandemics can be anticipated well before the death toll begins to mount. And health officials should begin to consider the production of emergency vaccines against all 15 existing HA subtypes of influenza virus. Also, given the existence of a vast number of influenza viruses in the aquatic wild-bird reservoir, we must accept the fact that they always pose pandemic threats. Thus, it is recommended that poultry (chickens, turkeys, etc.), domesticated ducks, and pigs be kept in ecologically controlled, secure houses with limited access to wild birds.
Animals ; Asian Continental Ancestry Group ; Birds ; Child, Preschool ; Disease Outbreaks ; Ducks ; Emergencies ; Genes, Viral ; Hong Kong ; Horses ; Humans ; Influenza A virus ; Influenza A Virus, H1N1 Subtype ; Influenza A Virus, H5N1 Subtype ; Influenza in Birds* ; Influenza, Human ; Male ; Mammals ; Orthomyxoviridae ; Pandemics* ; Pneumonia ; Poultry ; Swine ; Turkeys ; Vaccines ; Virulence