Scientific Information

Underlined words on this page are defined in our glossary.

The scientific name for the Step Study vaccine is Ad5 HIV-1 gag/pol/nef. It is composed of an adenovirus vector and an HIV gene insert.

A vector is used to carry a few non-reproducing HIV genes into the body to create an immune response. In this investigational vaccine, the vector is made from adenovirus type 5 (Ad5), a virus that causes the common cold and sore throats, but the vector has been crippled so that it cannot grow or spread in the body and it cannot cause you to get sick.

A synthetic insert consists of specific genes added to the vector. In this case, the genes added are HIV genes (gag, pol, and nef) which are man-made.

The experimental HIV vaccine should produce either antibodies or cytotoxic T cells (CTLs) to fight infection.

The experimental HIV vaccine is made from man-made materials that CANNOT cause HIV infection.