Data from: Safety and immunogenicity of H1/IC31®, an adjuvanted TB subunit vaccine, in HIV-infected adults with CD4+ Lymphocyte counts greater than 350 cells/mm3: a phase II, multi-centre, double-blind, randomized, placebo-controlled trial

Background: Novel tuberculosis vaccines should be safe, immunogenic, and
effective in various population groups, including HIV-infected
individuals. In this phase II multi-centre, double-blind,
placebo-controlled trial, the safety and immunogenicity of the novel
H1/IC31 vaccine, a fusion protein of Ag85B-ESAT-6 (H1) formulated with the
adjuvant IC31, was evaluated in HIV-infected adults. Methods: HIV-infected
adults with CD4+ T cell counts >350/mm3 and without evidence of
active tuberculosis were enrolled and followed until day 182. H1/IC31
vaccine or placebo was randomly allocated in a 5:1 ratio. The vaccine was
administered intramuscularly at day 0 and 56. Safety assessment was based
on medical history, clinical examinations, and blood and urine testing.
Immunogenicity was determined by a short-term whole blood intracellular
cytokine staining assay. Results: 47 of the 48 randomised participants
completed both vaccinations. In total, 459 mild or moderate and 2 severe
adverse events were reported. There were three serious adverse events in
two vaccinees classified as not related to the investigational product.
Local injection site reactions were more common in H1/IC31 versus placebo
recipients (65.0% vs. 12.5%, p = 0.015). Solicited systemic and
unsolicited adverse events were similar by study arm. The baseline CD4+ T
cell count and HIV viral load were similar by study arm and remained
constant over time. The H1/IC31 vaccine induced a persistent Th1-immune
response with predominately TNF-α and IL-2 co-expressing CD4+ T cells, as
well as polyfunctional IFN-γ, TNF-α and IL-2 expressing CD4+ T cells.
Conclusion: H1/IC31 was well tolerated and safe in HIV-infected adults
with a CD4+ Lymphocyte count greater than 350 cells/mm3. The vaccine did
not have an effect on CD4+ T cell count or HIV-1 viral load. H1/IC31
induced a specific and durable Th1 immune response.