Missing neutralizing activity change for PHE UK (2021)

[miseminger]

I temporarily moved this note to S_convalescent_plasma_binding.txt from S_convalescent_plasma_escape.txt (see commit 8cd2eca and commit 02aba7e):

# Sera from individuals who have been infected with Delta does not have strong
# neutralising activity against B.1.621
# PHE UK (2021) https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1009243/Technical_Briefing_20.pdf [Grey literature]
T95I;Y144delinsTSN;R346K;E484K;N501Y;D614G;P681H

# Sera from individuals who have been infected with Delta does not have strong
# neutralising activity against Beta.
# PHE UK (2021) https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1009243/Technical_Briefing_20.pdf [Grey literature]
L18F;D80A;D215G;L242del;R246I;K417N;E484K;N501Y;D614G;A701V

But I need to check what "does not have strong neutralising activity" means numerically and decide if this should go back into S_convalescent_plasma_escape.txt.