HIV-infected volunteers are continuing resist erosion of their Tcells two years after vaccination with a candidate AIDS vaccinemade by MicroGeneSys Inc.
The follow-up data, discussed in letters published this week inthe New England Journal of Medicine, indicated that volunteersin the Phase I study at Walter Reed Army Institute showedloss of CD4-bearing immune cells was 8.5 percent. Bycomparison, the loss was 26 percent in a matched group ofHIV-positive individuals.
Eight months after the vaccination, reported last June in theJournal, CD4 counts of the volunteers had declined 3 percentcompared with 8.7 percent in a matched group.
The antibody response to the HIV coat was boosted by thevaccine, and some volunteers produced neutralizing antibodiesto strains of the virus other than the one used to design thevaccine protein.
However, the capacity to neutralize different strains did notcorrelate with the production of antibodies to the V3 region ofthe coat. The V3 loop has been "the holy grail" of AIDS vaccinedesign, said MicroGeneSys President Frank Volvovitz, but thesedata suggest it may not be the key to effective vaccination.
The Meriden, Conn., company's vaccine consists of arecombinant form of the HIV protein gp160, a viral precursorto coat proteins in the mature virus.
A Phase II trial began last year, Volvovitz told BioWorld, with120 patients to be enrolled. The Phase I trial had consisted of30 HIV-infected volunteers.
-- Roberta Friedman, Ph.D. Special to BioWorld
(c) 1997 American Health Consultants. All rights reserved.