Comparison of nAb GMT and GMFR after booster with ARVAC CG or booster with BNT162b2.
SARS-CoV-2 RBD
TRANSFORMATION
Neutralizing antibody titers against the Ancestral (While GMFR in nAb titers against Ancestral, Gamma and Delta VOCs after a booster dose with BNT162b2 were similar to those elicited in the ARVAC CG cohorts (Transformation of nAb titers to IU/ml, allowed the evaluation of the percentage of participants with nAb levels associated with high VE. In group A, rates of participants with nAb levels higher than of 949 IU/ml before the booster were 26.7% (95% CI 39.0, 17.1), 3.3% (95% CI 11.4, 0.6), 6.7% (95% CI 15.9, 2.6), and 1.7% (95% CI 8.9, 0.1) for the Ancestral, Gamma, Delta, and Omicron BA.1 SARS-CoV-2 VOCs, respectively. These rates rose significantly after 14 days of having received the booster to reach 83.3% (95% CI 90.7, 72.0), 80.0 % (95% CI 88.2, 68.2), 60.0% (95% CI 71.4, 47.4), and 78.3% (95% CI 86.9, 66.4) for each viral variant, respectively. Likewise, in group B the proportion of participants with nAb levels higher than 949 IU/ml raised significantly from 15.0% (95% CI 5.2, 36.0), 0.0% (95% CI 0.0, 16.1), 5.0% (95% CI 0.3, 23.6), and 10.0% (95% CI 1.8, 30.1) for the Ancestral, Gamma, Delta, and Omicron BA.1 SARS-CoV-2 VOCs respectively at baseline, to 80.0% (95% CI 58.4, 91.9), 70.0% (95% CI 48.1, 85.5), 45.0% (95% CI 25.8, 65.8), and 95.0% (95% CI, 76.4, 99.7) for each viral variant, respectively (Supplementary Fig. A significant increase in the frequency of IFN-γ producing cells upon in vitro re-stimulation with SARS-CoV-2 RBD peptide pools was observed in both ARVAC CG cohorts in comparison with the levels observed before the booster. In addition, a slight increase of IL-4 producing cells was observed after the booster in group A participants (Fig. 