THERMAL INACTIVATION OF ORAL POLIO VACCINE - CONTRIBUTION OF RNA AND PROTEIN INACTIVATION

Heating the Sabin strains of poliovirus at 42 to 45 degrees C caused i nactivation, loss of native antigen, and release of the viral RNA (vRN A). The loss of virion infectivity exceeded the loss of vRNA infectivi ty (as measured by transfection) by roughly 2 log(10). Pirodavir inhib ited the loss of native antigen and RNA release and reduced the loss o f virion infectivity to the same level as the loss of vRNA infectivity . Thermoinactivation thus involves an RNA and a protein component, and pirodavir protected only against the latter.