Synthesis of hemagglutinin-binding trisaccharides

Abstract

Influenza or the flu, caused by RNA influenza viruses, is an infectious disease that affects birds and mammals, including millions of people each year. It causes severe respiratory illness and is sometimes fatal, especially to the elderly and children. There are three types of influenza viruses, A, B, and C [1], which are classified based on their major internal protein antigens. Influenza virus A is known to have a wide range of hosts and has been isolated from numerous animals, including humans, pigs, horses, felids, marine mammals, and birds [2-4], but influenza viruses B and C seem to exclusively infect humans [4, 5]. Wild aquatic birds, such as seagulls, ducks, geese, and shorebirds, are believed to be the natural reservoir of influenza virus A [1,2]. Among these three types, influenza virus A is the most virulent pathogen to humans, having led to millions of deaths in worldwide pandemics. For example, H1N1 (the Spanish flu), which belongs to the A type, caused 50-100 million deaths in 1918, and H2N2 (the Asian flu) and H3N2 (the Hong Kong flu) led to one million deaths in 1957 and 1968 [6,7], respectively. © 2011 Springer Science+Business Media, LLC.