Eastern and western strains of equine encephalitis virus are rapidly inactivated in acidic saline suspensions when such suspensions are agitated. The agitation may be produced by bubbling various gases through the suspensions or by mechanical shaking. By either method the rate of destruction of the virus infectivity appears to be nearly equivalent.
The H ion concentration of the viral suspension is the basic factor which influences the degree of susceptibility of the virus to bubbling or shaking. pH 6.4 appears to be the critical H ion concentration. Above this the virus is quite resistant, while at lower H ion concentrations it is readily susceptible to agitation inactivation.