Production of Influenza A Virus in the Cells of the Allantois

Abstract
The first cycle of influenza virus multiplication in the allantois may broadly be divided into three phases—the uptake of inoculated virus by the cells, the multiplication of this virus within the cells, and finally the liberation of newly-formed virus into the allantoic fluid. During much of the period of intracellular multiplication, little if any of the multiplying virus can be detected in the cells (1, 2), and the first sign that multiplication has occurred is the re-appearance of virus in suspensions of the allantoic membrane (3, 4). Some time later, virus can be detected in the allantoic fluid. If virus becomes detectable while still inside the cell, then this interval, between formation of detectable virus in the membrane and release of virus into the fluid, must comprise both the time required for detectable virus, once formed, to emerge on to the cell surface (the pre-emergence period) and the time required for emerged virus to elute from the cell surface into the fluid (the pre-elution period).