Extended Data Fig. 1: Molecular and structural characterization of the RBD–scNP.
From: Neutralizing antibody vaccine for pandemic and pre-emergent coronaviruses
a, Size-exclusion chromatography of RBD and ferritin sortase conjugation. The first peak shows conjugated protein. The second peak contains unconjugated RBD. b, Analytical size-exclusion trace shows a homogenous nanoparticle preparation. c, Negative-stain electron microscopy image of RBD–scNP on a carbon grid. Inset shows a zoomed-in image of RBD–scNP. The zoomed image shows RBD molecules arrayed around the outside of the ferritin nanoparticle. A representative image from the 31 images taken of the micrograph to visualize 13,827 total particles is shown. d, Chemical structure of 3M-052. Alum formulation of 3M-052 was used to adjuvant RBD–scNP immunization. e, RBD–scNP immunization regimen used for vaccination of cynomolgus macaques (n = 5). Blue arrows indicate time points for intramuscular immunizations with RBD–scNP (100 μg) adjuvanted with 3M-052 (5 μg 3M-052 plus 500 μg alum). BAL (orange arrows) and nasal swab (green arrows) fluids were collected 7 days before, 2 days after and 4 days after intratracheal and intranasal SARS-CoV-2 challenge (black arrow). f, S-2P mRNA-LNP prime and RBD–scNP boost vaccination of cynomolgus macaques (n= 5). Burgundy arrows indicate time points for S-2P mRNA-LNP immunization (50 μg mRNA dose). Blue arrows are the same as in a. Macaques were challenged 9 weeks after RBD–scNP boost (week 17 of the study). BAL and nasal swab fluids were collected as in a. Macaques were challenged at week 17 (black arrow). g, RBD mRNA-LNP immunization of rhesus macaques (n = 8). Tan arrows indicate time points for RBD mRNA-LNP immunization (50 μg mRNA dose). Blood was collected throughout each study as shown by red arrows in all panels.
