Fig. 1: RBD–scNP elicits extremely high titres of SARS-CoV-2-pseudovirus neutralizing antibodies.
From: Neutralizing antibody vaccine for pandemic and pre-emergent coronaviruses
a, SARS-CoV-2 RBD (blue and red)–H. pylori ferritin (grey) nanoparticle sortase (SrtA) conjugation. Model and two-dimensional class average of negative-stain electron microscopy (EM) of the resultant RBD–scNP are shown. b, Biolayer interferometry SARS-CoV-2 antibody and ACE2-receptor binding to RBD nanoparticles. nAbs, neutralizing antibodies; non-nAbs, non-neutralizing antibodies; non-nAbs IE, infection-enhancing non-neutralizing antibody; NTD, N-terminal domain. Symbols represent values from three independent experiments; data are mean + s.e.m. c, Design of the cynomolgus macaque immunogenicity and challenge study. d, Macaque serum IgG binding titre as area-under-the-curve (AUC) of the log10-transformed curve (log(AUC)) to recombinant SARS-CoV-2 S-2P, RBD, NTD and fusion peptide. Group mean ± s.e.m. are shown in d, e (n = 5 macaques). e, Plasma antibody blocking of SARS-CoV-2 S-2P binding to ACE2 and RBD neutralizing antibody DH1041. f, g, Dose-dependent serum neutralization of SARS-CoV-2 D614G pseudovirus infection of ACE2-expressing 293T cells (f) and neutralization ID50 and ID80 titres (g). Serum was examined after two immunizations. The mean value of duplicates is shown in f. h, SARS-CoV-2 D614G pseudovirus serum neutralization titre over time for individual macaques. i, Serum neutralization ID50 titres from macaques immunized twice with RBD–scNP (blue) or S-2P mRNA-LNP (burgundy). **P = 0.0079, two-tailed exact Wilcoxon test. n = 5 macaques. j, Serum neutralization titres for macaques immunized twice with RBD–scNP (blue) (n = 5 macaques) or humans with asymptomatic infection (n = 34 individuals) (A), symptomatic infection (n = 71 individuals) (S) or who were hospitalized (n = 60 individuals) (H). **P < 0.01, two-tailed Wilcoxon test. Horizontal bars are the group geometric mean in i, j. Pre-vaccination serum or neutralizing antibody spiked serum were used as controls in f–h. d, e, h, Arrows, time of immunization.
