By Tammy Gay

"The University of Kentucky was chosen as a participation site in this Merck vaccination study because of our past experience in testing HIV drugs."

-- Richard N. Greenberg, MD., principal investigator at UK of this study

February 26, 2002 (Lexington, Ky.) -- University of Kentucky College of Medicine Division of Infectious Disease researchers currently are recruiting healthy individuals to participate in a study of an HIV vaccine, sponsored by Merck and Co., Inc. Preliminary data about the Merck vaccine was released today to scientists world-wide through a major presentation at the Ninth Annual Conference on Retroviruses and Opportunistic Infections being held in Seattle, Wash.

This phase I clinical trial will test the safety and tolerability of two investigational HIV vaccines in 126 healthy individuals nationwide. UK is starting its volunteer recruitment efforts.

UK has participated in more than 50 HIV drug trials in the past 10 years. However, this will be the first trial involving healthy people, rather than HIV patients, said Richard N. Greenberg, M.D., professor of internal medicine in the UK College of Medicine and principal investigator of the study.

"The University of Kentucky was chosen as a participation site in this Merck vaccination study because of our past experience in testing HIV drugs," Greenberg said.

The two investigational vaccines will include an element of HIV known as Gag, or HIV-1 Gag DNA, a man-made copy of one of the HIV genes. Because the vaccines are man-made, they do not contain any live virus and will not result in HIV infection.

"The goal of the study is to evaluate the effect of these vaccines on the immune system's ability to produce T-cell responses and antibodies against HIV," Greenberg said. "We are starting to see responses to these vaccines that mimic similar responses in someone fighting HIV."

These two vaccines are different from earlier vaccines because they involve producing cytotoxic lymphocytes or CTLs, known as "killer cells," which destroy cells infected with a virus, killing them before they can reproduce. The earlier vaccines produced antibodies, which targeted the outer shell or envelope of the virus. So far, research efforts have found that antibodies alone are ineffective in protecting against HIV.

The new Merck vaccines target another arm of the immune system, the CTLs. CTLs now appear more likely to succeed in preventing or controlling HIV.

With the study vaccines, the Gag protein is put into a deactivated cold virus, the outer shell of an adenovirus. This outershell delivers the HIV protein to the body, exposing Gag to the immune system including CTLs. Then, the lymphocytes are put into a memory state, so if a person is exposed to the HIV virus, the cells should be ready to kill it.

In Kentucky, there were 2,560 people living with HIV as of June 2000, and 1,844 living with AIDS as of December 2001, according to the Centers for Disease Control and Prevention. UK's HIV health care providers follow more than 500 HIV cases.

During the study, neither the researcher nor the study participant will know whether the vaccine or a placebo is being administered until the study is complete.

Study participants must be a healthy adult, ages 18 to 50; have no history of chronic illness; weigh more than 110 pounds; not taking a daily prescription other than birth control pills; have no history of alcohol abuse; have not used IV drugs in the past year; have not had a sexual partner who is infected with HIV or is an active drug user; and has not been diagnosed or treated for a sexually transmitted disease in the last six months. Participants will be compensated for their time.

Anyone interested in participating in the study, should call (859) 323-3933 or (859) 323-6327.