Mix sugar, corn syrup and water in saucepan.
Cover; heat to rolling boil over medium heat.
Remove cover and boil rapidly to 242° on candy thermometer or until small amount of mixture dropped into very cold water forms a firm ball that holds its shape until pressed.
As mixture boils, beat egg whites until stiff peaks form.
Pour hot syrup very slowly in a thin stream into egg whites, beating constantly on medium speed.
Add vanilla; beat on high speed until stiff peaks form.