(PHOENIX, AZ) - An Arizona group is beginning experiments this month to determine whether a new vaccine could protect HIV-infected people from developing full-blown AIDS.
``It has a lot of promise, but we don't know if it's going to work,'' said Dr. Louis Kirby, president and founder of Pivotal Research Centers in Peoria and Mesa.
Pivotal is among 10 centers around the country studying the effectiveness of a vaccine developed by Merck Research Laboratories.
Merck has conducted four small trials on the vaccine, but this will be the largest.
The study calls for 167 participants, 16 of whom will come from the Phoenix metrpolitan area.
Participants must agree to receive four injections and make 17 visits to the Peoria center throughout the 78-week study.
None of the volunteers can be infected with HIV, because researchers are trying to determine whether the vaccine triggers an immune response.
Researchers then will study participants' blood to see if they've developed antibodies to the AIDS virus.
The experimental vaccine is engineered so it cannot give HIV to a healthy person.
The Merck vaccine stimulates a cellular immune response, a more robust immunity that would allow the human body to ward off several strains of the quickly mutating AIDS virus by enlisting the immune system's ``killer T cells'' and its ``helper cells.''
Researchers have been encouraged by the outlook for AIDS since a small group of rhesus monkeys were able to stave off the virus after receiving an animal-tested vaccine 11 months ago.
State health officials said there are more than 4,700 people in Arizona living with HIV.