Bioinformatics analysis
S protein reference sequences for SARS-CoV-1, SARS-CoV-2, batRaTG13, Middle East respiratory syndrome (MERS) and human common-cold coronaviruses 229E, NL63, OC43 and HKU1 were downloaded from the National Center for Biotechnology Information (NCBI). A multiple sequence alignment was created with multiple alignment using fast Fourier transform (MAFFT) using the slow but accurate L-INS-I parameter settings [24] and the alignment curated, cut to the target region 1029–1192 (SARS-CoV-1 numbering) and visualised with Jalview [25]. We used Molecular Evolutionary Genetics Analysis (MEGA) X [26] to calculate the number of amino-acid differences for all sequence pairs in the alignment of the mAb target region and the full S protein normalised by the length of the aligned sequence of the respective reference protein to obtain per cent amino acid identities.
To determine SARS-CoV-2 sequence diversity in the S protein within the current pandemic, 230 human and environmental viral sequences were downloaded from GISAID’s EpiCoV database on 1 March 2020. We gratefully acknowledge the authors, originating and submitting laboratories of the sequences on which this part of the research is based. The list is detailed in Supplementary Table 1. The nt sequences were searched with basic local alignment search tool (BLAST)X against the reference S protein. 174 hits covered the full length of the S protein and amino-acid mutations were counted and tabulated using a custom Perl script (Supplementary Table 2).