Figure 3.

Rises in serum respiratory syncytial virus (RSV)-neutralizing antibody titers, and incidences of medically attended acute RSV illness (RSV-MAARI), during the RSV season surveillance. Serum RSV-neutralizing antibody titer (PRNT₆₀) in sera collected pre- and postsurveillance are shown for vaccine (left) and placebo (right) recipients who had a postsurveillance ≥4-fold increase in either serum RSV PRNT₆₀ or anti-RSV F immunoglobulin G enzyme-linked immunosorbent assay titer. Dashed and solid lines indicate participants with and without RSV-MAARI during surveillance, respectively. Titers are expressed as the reciprocal log₂, but for ease of interpretation, titers corresponding to the arithmetic values are indicated for several participants.