Acid Sensitivity of the Influenza Virus Hemagglutinin

Abstract

Influenza virus hemagglutinin was shown to be acid resistant if precipitates which form during acidification are first removed. Adsorption of virus to precipitates formed during acidification may cause a virus to be described incorrectly as acid sensitive.

Simple method for the concentration of influenza virus from allantoic fluid on microporous filters

“…our laboratory for several years to concentrate and detect small numbers of virus in large volumes of water and wastewater (2, 4, 14; S. M. Goyal and C. P. Gerba, in B Dutka, ed., Membrane Filtration, Applications, Techniques, and Problems, in press). The methodology could not be applied to influenza virus, however, because it is very sensitive to extremes in pH (5), and low pH is necessary to enhance virus adsorption to negatively charged filters. The loss in hemagglutination (HA) titer upon acidification is believed to be due to the adsorption of virus to the precipitate that forms under acidic conditions (5).…”