Nasal IgA Ab titers before and after vaccination.
RSV IgA Abs
F-specific RSV IgA Abs by ELISA. Individual logOverall, the results suggested that BLB201 boosted RSV-specific nasal IgA levels in adults and elderly but to a lesser degree in elderly. Similar to results seen with systemic Ab responses, the fold increases in F-specific nasal IgA titers in both groups inversely correlated with baseline titers (fig. S2).