If you want to be absolutely sure about the safety, please use pasteurized egg whites for this frosting. (lowcarbsosimple.com)
I'm not that fond of using pasteurized egg whites that are bought in a little carton at the store since they don't whip well, for some reason; they only get frothy. (zscupoftea.com)
It is important to use pasteurized eggs in recipes that call for raw eggs because raw eggs are a known source of salmonella bacteria. (thespruce.com)