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

Influenza, caused by influenza virus, is a serious respiratory illness which poses a global public health threat. Vaccination is the primary strategy for the prevention and control of influenza. Although both inactivated vaccines and the live attenuated vaccines are effective in preventing influenza, the current vaccines have poor efficacy in the elderly and fail to provide protection against heterosubtype viruses. Development of a safer and more effective influenza vaccine that provides broad cross protection, overcoming the intrinsic limitation of the current vaccines, has been a scientific challenge. During the past decades, structural biology, reverse genetic and other virological technologies developed quickly and sped the progress of influenza vaccinology. Some new strategies for developing influenza vaccine have been generated, produced encouraging results, which showed great prospect as next-generation of influenza vaccines.
Disease Outbreaks ; prevention & control ; Hemagglutinin Glycoproteins, Influenza Virus ; immunology ; Humans ; Influenza Vaccines ; biosynthesis ; immunology ; Influenza, Human ; immunology ; prevention & control ; virology ; Orthomyxoviridae ; immunology ; Vaccines, Attenuated ; immunology ; Vaccines, Inactivated ; immunology

Humans ; Influenza A Virus, H1N1 Subtype ; immunology ; Influenza Vaccines ; chemistry ; immunology ; Influenza, Human ; immunology ; prevention & control ; Randomized Controlled Trials as Topic ; Vaccination

Seasonal influenza epidemics and influenza pandemics caused by influenza A virus (IAV) has resulted in millions of deaths in the world. The development of anti-IAV vaccines and therapeutics is urgently needed for prevention and treatment of IAV infection and for controlling future influenza pandemics. Hemagglutinin (HA) of IAV plays a critical role in viral binding, fusion and entry, and contains the major neutralizing epitopes. Therefore, HA is an attractive target for developing anti-IAV drugs and vaccines. Here we have reviewed the recent progress in study of conformational changes of HA during viral fusion process and development of HA-based antiviral therapeutics and vaccines.
Antiviral Agents ; therapeutic use ; Epidemics ; Hemagglutinins ; physiology ; Humans ; Influenza A virus ; immunology ; Influenza Vaccines ; immunology ; Influenza, Human ; immunology ; therapy ; Pandemics

Diphtheria-Tetanus-acellular Pertussis Vaccines ; Haemophilus influenzae type b ; immunology ; Influenza Vaccines ; Vaccination ; methods ; Vaccines, Combined

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

OBJECTIVEIn order to investigate the relationship between selection pressure and the prevalence of antigenic clusters, we sequenced and analyzed the H3N2 influenza virus from China between 1992 and 2012.

METHODSThe H3N2 influenza virus (n = 1206) in China from 1992 to 2012 was analyzed, include global selection pressure and sites positive selection pressure analysis.

RESULTSConsidering all the H3N2 influenza viruses during these 21 years, a total of four amino acid sites subject to positive selection. The global selection pressure varies with the variation of different antigenic clusters and three years with peak bottom selection pressure were identified.

CONCLUSIONThe global selection pressure rise from the peak bottom, a new antigenic clusters will appear andprevalent in the population, indicating the best time to replace the vaccine strain.

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

Computational Biology ; Epitopes, T-Lymphocyte ; Humans ; Influenza A Virus, H5N1 Subtype ; immunology ; Influenza Vaccines ; immunology

In Korea, several outbreaks of low pathogenic AI (H9N2) viral infections leading to decreased egg production and increased mortality have been reported on commercial farms since 1996, resulting in severe economic losses. To control the H9N2 LPAI endemic, the Korea Veterinary Authority has permitted the use of the inactivated H9N2 LPAI vaccine since 2007. In this study, we developed a killed vaccine using a low pathogenic H9N2 AI virus (A/chicken/Korea/ADL0401) and conducted safety and efficacy tests in commercial layer farms while focusing on analysis of factors that cause losses to farms, including egg production rate, egg abnormality, and feed efficiency. The egg production rate of the control group declined dramatically 5 days after the challenge. There were no changes in feed consumption of all three groups before the challenge, but rates of the control declined afterward. Clinical signs in the vaccinated groups were similar, and a slight decline in feed consumption was observed after challenge; however, this returned to normal more rapidly than the control group and commercial layers. Overall, the results of this study indicate that the safety and efficacy of the vaccine are adequate to provide protection against the AI field infection (H9N2) epidemic in Korea.
Animals ; Chickens ; Emulsions ; Female ; Influenza A Virus, H9N2 Subtype/*immunology ; Influenza Vaccines/*immunology/*standards ; Influenza in Birds/immunology/prevention & control ; Oviparity ; Specific Pathogen-Free Organisms ; Vaccines, Inactivated/immunology