First-in-Human Evaluation of the Safety and Immunogenicity of an Intranasally Administered Replication-Competent Sendai Virus-Vectored HIV Type 1 Gag Vaccine: Induction of Potent T-Cell or Antibody Responses in Prime-Boost Regimens.

Publication Type
Journal Article
Year of Publication
Nyombayire, Julien; Anzala, Omu; Gazzard, Brian; Karita, Etienne; Bergin, Philip; Hayes, Peter; Kopycinski, Jakub; Omosa-Manyonyi, Gloria; Jackson, Akil; Bizimana, Jean; Farah, Bashir; Sayeed, Eddy; Parks, Christopher L; Inoue, Makoto; Hironaka, Takashi; Hara, Hiroto; Shu, Tsugumine; Matano, Tetsuro; Dally, Len; Barin, Burc; Park, Harriet; Gilmour, Jill; Lombardo, Angela; Excler, Jean-Louis; Fast, Patricia; Laufer, Dagna S; Cox, Josephine H; S001 Study Team
J Infect Dis
Date Published
2017 Jan 01
Administration, Intranasal; Adult; AIDS Vaccines; CD8-Positive T-Lymphocytes; Female; Genes, Viral; Genetic Vectors; HIV Antibodies; HIV Infections; HIV-1; Humans; Immunity, Cellular; Immunity, Humoral; Immunization, Secondary; Immunogenicity, Vaccine; Kenya; Male; Middle Aged; Rwanda; Sendai virus; United Kingdom; Vaccines, DNA; Virus Replication

BACKGROUND:  We report the first-in-human safety and immunogenicity assessment of a prototype intranasally administered, replication-competent Sendai virus (SeV)-vectored, human immunodeficiency virus type 1 (HIV-1) vaccine.

METHODS:  Sixty-five HIV-1-uninfected adults in Kenya, Rwanda, and the United Kingdom were assigned to receive 1 of 4 prime-boost regimens (administered at 0 and 4 months, respectively; ratio of vaccine to placebo recipients, 12:4): priming with a lower-dose SeV-Gag given intranasally, followed by boosting with an adenovirus 35-vectored vaccine encoding HIV-1 Gag, reverse transcriptase, integrase, and Nef (Ad35-GRIN) given intramuscularly (SA); priming with a higher-dose SeV-Gag given intranasally, followed by boosting with Ad35-GRIN given intramuscularly (SA); priming with Ad35-GRIN given intramuscularly, followed by boosting with a higher-dose SeV-Gag given intranasally (AS); and priming and boosting with a higher-dose SeV-Gag given intranasally (SS).

RESULTS:  All vaccine regimens were well tolerated. Gag-specific IFN-γ enzyme-linked immunospot-determined response rates and geometric mean responses were higher (96% and 248 spot-forming units, respectively) in groups primed with SeV-Gag and boosted with Ad35-GRIN (SA and SA) than those after a single dose of Ad35-GRIN (56% and 54 spot-forming units, respectively) or SeV-Gag (55% and 59 spot-forming units, respectively); responses persisted for ≥8 months after completion of the prime-boost regimen. Functional CD8 T-cell responses with greater breadth, magnitude, and frequency in a viral inhibition assay were also seen in the SA and SA groups after Ad35-GRIN boost, compared with those who received either vaccine alone. SeV-Gag did not boost T-cell counts in the AS group. In contrast, the highest Gag-specific antibody titers were seen in the AS group. Mucosal antibody responses were sporadic.

CONCLUSIONS:  SeV-Gag primed functional, durable HIV-specific T-cell responses and boosted antibody responses. The prime-boost sequence appears to determine which arm of the immune response is stimulated.