Studies on the Infectivity of Vaccinal Elementary Bodies

Abstract

Under the described exptl. conditions, an avg. of 366 elementary bodies in purified suspension behaved as an infectious unit. In all expts., the frequency distribution of positive and negative inoculations with the successive dilutions of elementary body suspensions followed the curve to be expected if a single elementary body is capable of causing an infection. The observed infectivity of vaccinia virus is greatly dependent on exptl. conditions. Under ideal circumstances a single elementary body may possibly behave as an infectious unit.