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Published byGriselda Gilbert Modified over 9 years ago
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Antigenic Shift v. Drift in Avian and Mammalian Sino- Influenza Type A Viruses. By Charles Hauser, St. Edward’s University Mark Maloney, Spelman College Young Kim, Northland College Michael P. Saclolo, St. Edward’s University
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Issues Role of viral hemagglutinin diversity in pathology Creation of new viral strains Antigenic shift versus drift
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Influenza type A Subtypes designated by Hemagglutinin (H) and Neuraminidase (N) expression
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Subtypes H and N are on surface H and N are components of flu vaccines Subtypes A (H1N1) and A (H3N2) are common human viruses
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Vaccines must match subtype and specific strain New flu viruses evade immunity: –Antigenic Shift vs. –Antigenic Drift
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Antigenic Shift New subtypes match different H and N genes Avian and human viruses mix and match in swine
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Antigenic Drift Small differences in sequence within a subtype define strains “alleles” or different versions of same H genes
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BIRD FLU “Bird flu” is unusual Some strains of avian subtypes (H5N1, H9N2, H7N7) can directly infect humans
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Module Components Chinese Avian and Mammalian Influenza Hemagglutinin Sequences ClustalW Alignment Dendogram Analysis
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H5N1 H9N2 H3N2 H1N1
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