VOLUME 14 NUMBER 1 (January to June 2021)

Cecilia P. Mikita¹ and Eduardo A. Padlan*^,2

¹Walter Reed National Military Medical Center,
      Department of Medicine,
      Allergy/Immunology/Immunizations Service,
      4954 North Palmer Road, Bethesda, MD 20889-5600, USA
²4006 Simms Drive, Kensington, MD 20895-1336, USA

A possible subunit vaccine that focuses the immune response to the receptor-binding site of the spike glycoprotein of SARS-CoV-2 is designed. Sequence and three-dimensional structural data are used to map the epitopes of neutralizing antibodies on a suitable spike protein for use as a subunit vaccine. The chemical reactivity of the residues in the spike protein is reduced by judicious amino acid replacements, except for the residues in the epitopes. This results in a molecule that would elicit an immune response directed at the known epitopes. The proposed subunit vaccine is expected to work regardless of the existence of mutations in one or more, but not all, of the epitopes, as well as elsewhere in the spike protein. The amino acid sequence of the proposed vaccine may serve as the starting point for even more efficacious vaccines if more neutralizing antibody epitopes are included.