Fig. 2. The Omicron variant evades immunity due to mutations localized not only in the RBD but also in the NTD.

(A to C) Reciprocal dilution of 50% neutralization titer (NT₅₀) values were determined in 293T/ACE2 cells for serum samples isolated from 12 individuals 3 months after two doses of BNT162b2 vaccination (A), convalescent serum from 11 patients infected with the Alpha variant (B), and 18 patients infected with the Delta variant (C). (D) Neutralization efficacy in 293T/ACE2 cells is shown for 12 vaccinated serum samples against parental virus (D614G mutation), parental virus with replacement with Omicron’s NTD, Omicron, and Omicron with replacement with parental NTD. The NT₅₀ values are summarized in the right panels. n = 3 technical replicates. P-values were determined by two-sided paired t-tests. Dotted lines indicate detection limit.