Introduction: In particular,
P681H is located in the cleavage site of the S1-S2 subunits of the
spike and is observed in other variants, including the recently emerging Omicron variant.
Introduction: These include the substitutions
N501Y and
E484K, which are present in the Beta, Gamma, Theta, and Omicron variants,
F490S, which is present in the Lambda variant, and
P681H, which is present in the Lambda and Omicron variants.