Many New S mutations in Delta in US
https://github.com/cov-lineages/pango-designation/issues/188 This was always to be expected as Delta encountered a larger, more densely vaccinated population, but it's still happening with remarkable speed. There is still no change in the RBD, as I had predicted, but S:L5F is unique. It's in the signal sequence for the S protein and thought to increase viral secretion further. It is a part of B.1.526(Iota). https://europepmc.org/article/PPR/PPR180476 https://outbreak.info/situation-reports?muts=S%3AL5F Most of the others are in the S2 subunit, indicating that Delta is taking full advantage of P681R and syncytia. N1074S appears to be becoming fixed, and it had appeared in no lineage before B.1.617.2. Its increased viability is almost certainly tied to P681R given its position in the S2 subunit. https://outbreak.info/situation-reports?muts=S%3AN1074S Q613H never appeared in a really dominant A or B strain, but it was theorized to have worked in roughly the same ...