Figure 4.

Fold-decrease in neutralization titers of Omicron relative to Delta 3 months after booster BNT162b mRNA vaccine dose in NH residents.

Individual values and fold-decrease in geometric mean neutralization titers (GMNT) of Omicron relative to Delta in NH residents without (naive, blue) or with (recovered, red) COVID-19 before initial vaccination is shown as a number with ‘‘x’’ symbol. Patients without detectable antibodies were not included in the GMNT reduction calculation. Wilcoxon signed rank test was used for within-subjects comparisons in titers found with Delta and Omicron variants 3 months after the boost vaccine dose. ****p-values < 0·0001.