Evaluation of the Safety of a Polyvalent Virus in Healthy Adults

This is a research study to evaluate the safety of a vaccine to protect people from HIV infection. Human Immunodeficiency Virus (HIV) is the cause of AIDS (Acquired Immune Deficiency Syndrome). AIDS is one of the most serious viral infections of our time. It is believed that all persons who contract HIV will eventually develop AIDS. Because of this, we are trying to develop new ways to prevent infection with HIV. Vaccines have been very successful in preventing or decreasing the symptoms of a number of other viral infections such as hepatitis B, polio, and measles. Viral vaccines work by causing a person's immune system to make antibodies and immune cells against the virus or to "respond" to the virus. Because of the success with other viral infections, scientists are trying to develop a successful vaccine for HIV. The vaccine that will be tested in this study has been prepared from a small part of the HIV. The part of the HIV used in this vaccine is the "envelope" or coating part of the virus. Because only this one part of the virus is used in the vaccine, the vaccine cannot cause HIV infection. The "envelope" part of HIV has been put into another virus, the vaccinia virus. The vaccinia virus has been used as a vaccine for many decades in millions of people and is the vaccine that eliminated the disease known as smallpox (i.e. smallpox vaccine). The smallpox vaccine is a licensed and effective vaccine. Making a new vaccine by putting part of a different virus into the smallpox vaccine (also known as vaccinia virus) is called a "recombinant" vaccinia virus vaccine. Our new recombinant vaccine product is called PolyEnv1. In this study, researchers will evaluate how well the vaccine is tolerated, how much vaccine should be given, and determine if any side effects occur in response to the vaccination.