background in the influenza a viruses, neuraminidase (na), hemagglutinin (ha), pb2, ns1 and m are responsible for the disease pathogenicity. the mechanism of pathogenicity differs among these viruses. binding of host proteases by the viral na, sequence of ha in the cleavage and receptor-binding sites, number of oligosaccharide side chains of ha, shortening of na, and substitutions in pb2, ns1 a...

Background: The pandemic and regional influenza outbreaks resulting from antigenic variation of influenza viruses have been the subject of numerous studies which are crucial to the preparation of the vaccine. Frequent global winter outbreaks of influenza viruses require a constant surveillance of emerging influenza variants in order to develop efficient influenza vaccine. Methods: This study wa...

Antibody-dependent enhancement of the uptake of influenza A virus by Fc receptor-bearing cells was analyzed by using virus strains of the three human influenza A virus subtypes, A/PR/8/34 (H1N1), A/Japan/305/57 (H2N2), and A/Port Chalmers/1/73 (H3N2). Immune sera obtained from mice following primary infection with an H1N1, H2N2, or H3N2 subtype virus neutralized only virus of the same subtype; ...

The H3N8 virus and the H3N2 virus are the main subtypes of canine influenza virus (CIV). H3N8 CIV mainly circulates in America, and H3N2 CIV mainly circulates in Asia. However, there was an outbreak of the Asian H3N2 virus in the United States (US) in 2015. Thus, it is important to evaluate the presence of subtype H3N8 virus in dogs in China. From May 2015 to November 2015, 600 sera from pet do...

H3 subtype avian influenza virus (AIV) poses a great threat to public health, and so investigating its epidemiology is of great importance. A novel reassortant H3N2 AIV strain was isolated from a live poultry market in eastern China. The strain's genes originated from H1N1, H3, and H7 AIVs. Thus, the genome information of the H3N2 isolate will help to investigate further the epidemiology of H3 ...

Background. Influenza causes various seasonal respiratory diseases, resulting in significant morbidity and mortality children. is a highly contagious disease causing global pandemics. This study aimed to investigate the frequency outcome of influenza children admitted Tabriz Children's Hospital. Methods. cross-sectional included suspected patients Medical Center between 2014 2019 diagnosed with...

Triple reassortant influenza A viruses (IAVs) of swine, particularly the North American H3N2 subtype, circulate in swine herds and may reassort and result in the emergence of novel zoonotic strains. Current diagnostic tools rely on isolation of the viruses, followed by serotyping by hemagglutination or genome sequencing, both of which can be expensive and time-consuming. Thus, novel subtype-spe...

Sera of persons of different age groups collected in 1976, 1978 and 1979 were tested for the presence of HI antibodies against various strains of the H3N2 and H1N1 subtypes of influenza virus. The occurrence of infection by H3N2 subtype was recorded during the 1976-1978 period but in 1979, circulation of this subtype of virus was limited. The prevalence of antibody against A/São Paulo/1/78 (H1N...

C4b Binding Protein (C4BP) is a major fluid phase inhibitor of the classical and lectin pathways complement system. Complement inhibition achieved by binding to restricting role activated component C4b. C4BP functions as co-factor for factor I in proteolytic inactivation both soluble cell surface-bound C4b, thus formation C3-convertase, C4b2a. also accelerates natural decay/dissociation C3 conv...