Vaccination with a modified vaccinia virus Ankara MVA vectored HIV 1 immunogen induces modest vector specific T cell responses in human subjects
We investigated whether vaccination of healthy HIV-seronegative and HIV-1-seropositive antiretroviral therapy-treated subjects with recombinant modified vaccinia virus Ankara expressing an HIV-1 immunogen (MVA.HIVA) induced MVA-specific T cell responses. Using IFN-γ Elispot assays, we observed new or increased responses to MVA virus in 52% of HIV-seronegative subjects and 93% HIV-1 seropositive subjects; MVA-specific T cell frequencies were generally low and correlated poorly with T cell responses to the HIV-1 immunogen. In two vaccinees, responses were mapped to CD8+ T cell epitopes present in replication-competent vaccinia virus. These data support further evaluation of MVA as a viral vector for HIV-1 immunogens.
Howles S, Guimarães-Walker A, Yang H, Hancock G, di Gleria K, Tarragona-Fiol T, Hayes P, Gilmour J, Bridgeman A, Hanke T, McMichael A, Dorrell L