One of the earliest methods used in the manufacture of stable and safe vaccines is the use of chemical and physical treatments to produce inactivated forms of pathogens. Vaccine development is a complex and time-consuming process that differs from the development of conventional drugs. The need for a safe, effective and affordable HIV vaccine has never been greater. In 2004 almost five million people became infected with HIV. In addition, providing access to antiretrovirals in Africa remains a huge challenge. Vaccines are one of the most effective, affordable and beneficial tools in public health. The World Health Organization (WHO) estimates that global immunization campaigns save more than 2.5 million lives every year and protect millions more from disease and disability. In addition to being relatively inexpensive, vaccines are remarkably cost-effective.