Fig. 5: Correlation between neutralizing antibody titers and protection against BA.5.

a–i Correlation between the FRNT₅₀ neutralization titers at 3 months post-boost (pre-challenge) against BA.5 (x-axis) and the infectious virus loads (y-axis) detected at 4 dpi in (a, d, g) nasal washes, (b, e, h) trachea, and (c, f, i) lungs of hamsters primed with (a–c) one 10¹⁰ vp dose of Ad26.COV2.S (n = 6 or 7 per group), (d–f) one 10⁸ vp dose of Ad26.COV2.S (n = 6 or 7 per group), or g–i two 5 μg doses of BNT162b2 (n = 6 or 7 per group). j Proportion of hamsters developing breakthrough infections following BA.5 challenge. Percentage (%) and number of animals with detectable infectious virus loads in at least one sample (nasal wash, trachea, and/or lungs) are shown below each graph. Colors designate experimental cohorts (n = 6–7 animals per group). In panels a–i, data points represent individual animals, thick lines represent linear regression, dashed lines with shading represent 95% CI, and dotted lines represent the lower limit of detection for each assay. Spearman’s rank correlation coefficient (r) and p-values are shown. In panel j, the color-coded portion of the ring represents the proportion of hamsters developing a breakthrough infection following BA.5 challenge. Panels were generated using GraphPad Prism v9.4 software. See Source Data for complete data.