Safe and effective HIV vaccines offer the most hope of stopping the spread of HIV disease worldwide. Although HIV transmission is in theory largely preventable, in practice, without the development of an effective vaccine, HIV will continue to infect millions throughout the world. The ideal vaccine for worldwide use will be inexpensive to manufacture, provide protection against all subtypes of HIV, require minimal if any boost, protect against all methods of spread of HIV for years, and be easily administered, stable to heat, and widely accessible (Merigan et al., 1999). …