Figure 4. Remaining Immunity to the Spike Protein of the Omicron Variant.

Fraction of preserved CD4⁺ (A) and CD8⁺ (B) reactivity to the whole spike protein in each group, after having subtracted loss of reactivity to the mutated regions. 2 Doses indicates individuals with 2 doses of vaccine; 3 Doses, 3 doses of mRNA vaccine; COV-VAC, individuals who had contracted and recovered from SARS-CoV-2 and were subsequently vaccinated; HET, heterologous vaccination with adenoviral vector followed by an mRNA vaccine; and VAC-COV, individuals who had been vaccinated and who had subsequently been infected with SARS-CoV-2.