Figure 1.

(a) Study schedule. Two groups (N = 6) were vaccinated (V) or administered PBS (I) twice, four weeks apart. Fourteen days post each vaccination, exams (E) were performed. The presence of SARS-CoV-2 spike-specific binding (b) and neutralizing (c) antibodies in serum obtained from rhesus macaques at time of vaccination and 14 days afterwards were measured using ELISA and infectious virus neutralization assays. (d) SARS-CoV-2 S-specific T cell responses were measured via ELIspot. Closed red circles = animal positive in ELISA assay; open red circle = animal negative in ELISA assay; blue triangles = control animals; grey triangles = convalescent human sera; dotted line = lower limit of detection.