This version is not peer-reviewed
Potential for Developing the SARS-CoV Receptor Binding Domain Recombinant Protein (RBD) as a Heterologous Human Vaccine for SARS-CoV-2
: Received: 25 February 2020 / Approved: 29 February 2020 / Online: 29 February 2020 (03:20:37 CET)
: Received: 2 March 2020 / Approved: 4 March 2020 / Online: 4 March 2020 (05:19:16 CET)
A peer-reviewed article of this Preprint also exists.
Journal reference: Human Vaccines & Immunotherapeutics 2020
A SARS-CoV receptor-binding domain (RBD) recombinant protein was developed and manufactured under current good manufacturing practices in 2016. The protein known as RBD219-N1 when formulated on Alhydrogel®, induced high-level neutralizing antibodies and protective immunity with low immunopathology in mice after a homologous virus challenge with SARS-CoV (MA15 strain). In this report, we examined published evidence in support of whether the SARS-CoV RBD219-N1 could be repurposed as a heterologous vaccine for SARS-CoV-2. Our findings include evidence that convalescent serum from SARS-CoV patients can neutralize SARS-CoV-2. Additionally, a review of published studies using monoclonal antibodies (mabs) raised against SARS-CoV RBD and that neutralize the SARS-CoV virus in vitro, finds that some of these mabs bind to the receptor-binding motif (RBM) within the RBD, while others bind to domains outside this region within RBD. This information is relevant and supports the possibility of developing a heterologous SARS-CoV RBD vaccine, especially due to the finding that the overall high amino acid similarity (82%) between SARS-CoV and SARS-CoV-2 spike and RBD domains is not reflected in RBM amino acid similarity (59%). However, the high sequence similarity (94%) in the region outside of RBM offers the potential of conserved neutralizing epitopes between both viruses.
heterologous vaccine; receptor-binding domain; subunit vaccine; coronavirus; COVID-19; SARS; SARS-CoV-2
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
We encourage comments and feedback from a broad range of readers. See criteria for comments and our diversity statement.