Table 2:
Neutralizing antibody responses to RSV by infection statusa
| GMNAT log2 (95% CI) | Fold Change | |||||
|---|---|---|---|---|---|---|
| RSV/B/18537 | 1st Visit | 2nd Visit | 3rd Visit | Visit 1 to 2 | Visit 1 to 3 | Visit 2 to 3 |
| Uninfected | 9.1 (7.9–10.2) | 9.1 (8.1–10.1) | 9.0 (8.0–10.0) | 1.05 | 0.97 | −1.08 |
| Acutely Infected | 7.6 (6.4–8.8) | 10.6 (9.6–11.6) | 10.8 (9.2–12.3) | 8.08 | 8.70 | 1.08 |
| Recently Infected | 10.5 (9.3–11.7) | 7.2 (6.4–7.9) | 7.0 (4.8–9.2) | −10.05 | −11.55 | −1.15 |
| RSV/B/Buenos Aires | ||||||
| Uninfected | 9.0 (8.2–9.8) | 8.8 (8.0–9.6) | 8.7 (7.8–9.5) | 1.16 | 1.3 | −1.13 |
| Acutely Infected | 8.0 (6.7–9.3) | 9.8 (8.4–11.1) | 9.6 (8.9–10.4) | 3.37 | 3.13 | −1.08 |
| Recently Infected | 9.7 (8.2–11.1) | 7.5 (5.3–9.7) | 7.0 (4.8–9.2) | −4.55 | −6.45 | −1.42 |
| RSV/A/Tracy | ||||||
| Uninfected | 9.2 (8.4–9.9) | 9.2 (8.3–10.1) | 9.3 (8.6–10.0) | 1.01 | 1.1 | 1.08 |
| Acutely Infected | 9.0 (6.4–11.6) | 10.8 (8.3–13.2) | 10.8 (7.8–13.7) | 3.43 | 3.35 | −1.02 |
| Recently Infected | 10.8 (7.2–14.4) | 8.5 (6.3–10.7) | 8.3 (7.6–9.1) | −4.93 | −5.43 | −1.1 |
| RSV/A/Ontario | ||||||
| Uninfected | 7.5 (7.0–8.0) | 7.6 (7.1–8.2) | 7.6 (7.0–8.3) | 1.09 | 1.07 | −1.01 |
| Acutely Infected | 7.5 (5.4–9.6) | 8.9 (6.4–11.3) | 8.6 (6.0–11.3) | 2.57 | 2.13 | −1.21 |
| Recently Infected | 8.0 (6.8–9.2) | 7.3 (6.6–8.1) | 6.7 (5.2–8.1) | −1.58 | −2.53 | −1.6 |
Geometric mean neutralizing antibody titers (log2) and fold change for each group of volunteers to prototypic (RSV/B/18537 and RSV/A/Tracy) and contemporaneous (RSV/B/Buenos Aires and RSV/A/Ontario) isolates.
a
Infection status was defined by either an RSV-positive acute respiratory illness or changes in neutralizing antibody titers and includes: uninfected (n = 12), acutely infected (n = 4), and recently infected (n = 3). Fold change in neutralizing antibody titer between study visits is shown. GMNAT, geometric mean neutralizing antibody titer; CI, confidence interval.