The Vietnam War lasted ten thousand days, and involved over one million US military personnel. No list exists, but thousands, perhaps tens of thousands were awarded.
Any soldier who is injured during combat as a direct result of something the enemy did is awarded the Purple Heart. In other words, someone who was crossing the street in Vietnam and hit by a car, or...
Anyone that was wounded in combat. It was awarded to thousands during the Vietnam War. Everyone on the Wall in Washington received it, plus the tens of thousands that were not fatally wounded.