I've been buying Davidson's pasteurized eggs for things like
this. I have couple of old family frosting recipes that call for either a whole egg or egg whites. I tried pasteurizing them myself but didn't feel confident enough that they would be safe. My daughter-in-law got quite sick from eating raw cookie dough once, so I'm a little squeamish. The pasteurized eggs are a bit pricey, but I freeze them for future use.