A group from Fred Hutchinson Cancer Research Center, Seattle, USA, etc. has reported that epitopes in SARS-CoV-2 S2 can serve as blueprints for the design of immunogens capable of eliciting cross-neutralizing coronavirus antibodies.
https://pubmed.ncbi.nlm.nih.gov/34237283/
From 198 antibodies isolated from four COVID-19+ convalescent patients, 14 SARS-CoV-2 neutralizing antibodies were isolated. One targeted the N-terminal domain (NTD), one recognized an epitope in S2, and 11 bound the receptor-binding domain (RBD), and those IC50s ranged from 0.007 μg/ml to 15.1 μg/ml.
The S2 subunit contains at least one epitope that, although poorly immunogenic, is present on four of five human beta coronaviruses SARS-CoV-1, SARS-CoV-2, OC43, HKU1). That epitope, as defined by its recognition by CV3-25, is a valid candidate for the development of a global coronavirus vaccine. IC50 of C3-25 against SARS-CoV-2 was 0.34 μg/ml.
