The section Direct evidence of reactivity to HCoV epitopes homologous to SARS-CoV-2 epitopes [1]: > we designed a peptide pool encompassing peptides homologous

The section Direct evidence of reactivity to HCoV epitopes homologous to SARS-CoV-2 epitopes [1]: > we designed a peptide pool encompassing peptides homologous to CD4-R30 epitopes, derived from HCoV-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1 and several other HCoVs (see Methods), for a total of 129 HCoV homologs (HCoV-R129; table S2). Similarly, we synthesized a pool that encompassed peptides homologous to the SARS-CoV-2 CD4-S31 epitope pool, consisting of potential epitopes derived from other HCoVs, for a total of 124 HCoV homologs (HCoV-S124; table S3). The "speculation" disclaimer, IMHO, is based on the assumption that the designed peptide pools invoke responses similar to their viral homologs. I have no issue with the "direct evidence" heading as this research makes an important step in demonstrating cross-reactivity. Teasing out the degree of protection this cross-reactivity provides in real-world populations is a much harder problem. [1] https://science.sciencemag.org/content/early/2020/08/04/science.abd3871#sec-4 https://science.sciencemag.org/content/early/2020/08/04/scie...