ERVW-1 and infection: This is the case of the Australian cohort characterized by invalidating alterations in the nef gene or the Spanish LTNP-C cluster with a heritable conserved non-functional env gene, which is responsible for the low binding of the viral Env complex to CD4, inefficient cell-signaling and subsequent impaired fusion, infection and viral transmission capacities (Zaunders et al., 2011; Casado et al., 2018; Lopez-Galindez et al., 2019; López-Galíndez, 2019).