Figure 3. Filovirus and LASV GP–specific neutralization antibody responses in macaques immunized with the quadrivalent vaccine.

At study days 0 and 56, macaques were immunized i.m. with 4 × 10⁷ PFU of the quadrivalent vaccine (black circles) or rVSV N4CT1-HIVgag as control (gray squares). A total of 20 vaccinated animals and 12 control animals are represented, except as noted. At study days 0, 10, 28 (only from SUDV and MARV challenge monkeys), 56, and 66, sera were collected and tested for (A) LASV-, (B) EBOV-, (C) SUDV-, and (D) MARV-specific neutralization responses. Data represent the geometric mean of log-transformed LASV and filovirus neutralization titer (FRNT50), with the 95% confidence interval. An unpaired 2-tailed t test was used to determine statistically significant differences (**P < 0.005, ***P < 0.0005) between quadrivalent and control groups as indicated. Mean values and standard deviations are depicted in red.