"The neuraminidase story started in the 1940s when George Hirst, working in the Rockefeller Institute in New York, reported that when allantoic fluid from flu virus infected eggs was mixed with red blood cells in ice the cells were very heavily agglutinated. If these agglutinated cells were warmed to 37 degrees they dispersed and could not be re-agglutinated in the cold by fresh virus. Hirst took this to mean that the virus had an enzyme which destroyed receptors for the virus on the red cell. Shortly after, MacFarlane Burnet (the same MacFarlane Burnet who demonstrated that there were several strains of poliovirus), in the Walter and Eliza Hall Institute in Melbourne, found that Vibrio cholerae secreted an enzyme which did the same thing and this enzyme became known as receptor destroying enzyme or RDE. Burnet was immensely curious about the nature of the substrate for RDE and persuaded (ordered, more likely !) a biochemist, Alfred Gottschalk who was working on yeast fermentation in the Institute, to stop working on yeast and find out what reaction RDE catalyzed."

"It had been generally accepted that the agglutination of red cells by flu virus was due to the sialidase (neuraminidase) on the virus binding to its substrate, sialic acid, on the surface of the cell. This idea persisted for some time until, in 1961, the first doubts started to appear. Mayron and his colleagues showed that a soluble sialidase could be separated from the PR8 influenza virus and it did not adsorb to red cells (Mayron, L. W., Robert, B., Winzler, R. J. and Rafelson, M. E. Arch. Biochem. Biophys. 92: 475- 483, 1961). In 1962 in a more elegant experiment, Hans Noll found that treating flu B virus with trypsin liberated almost 100% of the neuraminidase as a soluble molecule with sedimentation coefficient of 9S (about 200,000 Mol Wt) leaving all of the haemagglutinin activity still associated with the virus particle (Noll, H., Aoyagi, T. and Orlando, J. Virology 18: 154-157, 1962)."