Figure 1.

SARS-CoV-2 antibody responses in macaques after vaccination. (a) Virus neutralizing antibody titers against Wuhan, Alpha and Delta variants of SARS-CoV-2 virus in macaques on days 14 and 28 after initial immunization with 5 and 25 µg NARUVAX-C19 vaccine; (b) Anti-rSpike IgG antibody titers in macaques at days 0, 14, 21, and 28 after primary immunization (c) RBD-ACE2 blocking antibody levels in macaques at day 28 after primary immunization. RBD-ACE2 blocking antibodies were determined according to the level of inhibition: negative (<30%), low (30-59%), medium (60-89), and high (90≤). Differences in the studied variables between animal groups were assessed using Tukey’s multiple comparisons test. A P < 0.05 value was considered a significant difference. **P < 0.01, ***P < 0.001, and ****P < 0.0001.