Similar title to Adams, B. & Sasaki, A. ORCID: https://orcid.org/0000-0003-3582-5865 (2009). Antigenic distance and cross-immunity, invasibility and coexistence of pathogen strains in an epidemiological model with discrete antigenic space. Theoretical Population Biology 76 (3) 157-167. 10.1016/j.tpb.2009.06.001.