Multiplicity Reactivation of Influenza Virus

Abstract

Influenza A virus, inactivated by heat or formaldehyde, does not multiply when inoculated into the allantois. Yet, such an inoculum will increase the apparent yield of a subsaturating inoculum of live virus by preventing its combination with uninfected cells. This effect may be mistaken for multiplicity reativation. By preventing adsorption of newly released particles to uninfected cells, the receptor-destroying enzyme of Vibrio cholerae can, with certain virus strains, imitate the effect of inactivated virus. Influenza virus particles, produced in the first cycle following a subsaturating inoculum, adsorb on to uninfected cells very soon after they become hemagglutinating.