First, the concept that a “T-cell vaccine” can affect HIV disease in humans remains unproved. Only one T-cell vaccine, Merck’s MRKAd5 HIV-1 gag/pol/nef trivalent vaccine, has been tested, in two efficacy trials. The first was referred
to as the STEP trial (ClinicalTrials. gov number, NCT00095576) and was conducted in North America, South America, the Caribbean, and Australia; the second, called Phambili (ClinicalTrials.gov number, NCT00413725), was conducted
in South Africa.