VIG is purified from human blood and used to treat serious infections of the vaccinia (smallpox vaccine) virus or similar viruses. It is the only treatment available for those viruses. The only available supply of VIG has developed a discoloration over time and therefore is considered an investigational new drug by the FDA. This study will allow it to be used for intramuscular injection in a controlled setting for people who may need it [during HIV vaccine research].