Stephen J.LurieMD, PhD, Senior EditorIndividualAuthorJody W.ZylkeMD, Contributing EditorIndividualAuthor
To the Editor: In the study by Dr Kahn and colleagues,1 both the control and treatment groups were given incomplete Freund adjuvant (IFA), with the treatment group receiving viral antigen in addition to the adjuvant. The purpose of adjuvants is to increase the potency of vaccines, since particulate antigens alone are weak immunogens. Incomplete Freund adjuvant is a water-in-oil emulsion that may produce an immune response for as long as 6 months.2 It has been shown that IFA without antigen increases cytokine messenger RNA production of 6 interleukins (IL-1, IL-2, IL-4, IL-5, IL-6, and IL-13) in mice.3 Thus it appears that both the control and treatment groups in the study by Kahn et al were treated with an active and durable immunomodulating agent.
Goldberg B, Stricker RB. Outcomes of a Trial of HIV-1 Immunogen in Patients With HIV Infection. JAMA. 2001;285(17):2191-2195. doi:10.1001/jama.285.17.2191