While this is true for RAW egg whites, the majority of egg whites in a carton are pastuerized which neutralizes the Avidin in the egg white making it easier to digest and kills salmonella
Well two things
1- most eggs, more like 98% are not sold as pasteurized eggs
2- the ozone / gas pressure treatment by which eggs are treated for salmonella would have no effect on avidin. Studies have demonstrated quite conclusively that only temps about 70 celcius / 185 f would allow for enough denaturation of the biotin binding protein- avidin.
Some studies even suggest that cooking and egg for no less than 25 minutes at temps between 185-190 would still leave 30% of the avidin available for binding.
Durance, T.D.; Wong, N.S. (1992). "Kinetics of thermal inactivation of avidin". Food Research International 25 (2): 89–92. doi:10.1016/0963-9969(92)90148-X.