Table 1.
Antibody avidity over time among one-dose and three-dose participants who were HPV16 seronegative at first HPV vaccination.
| One-dose (N = 747 samples) | Three-dose (N = 1115 samples) | One-dose/Three-dose | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Year of follow-up | n | GMA (95% CI) | IQR | % change† | n | GMA (95% CI) | IQR | % change† | Ratio (95% CI) |
| Year 1 | 52 | 2.39 (2.13–2.68) | 2.25–3.07 | N/A | 161 | 2.87 (2.80–2.94) | 2.68–3.16 | N/A | 0.83 (0.74–0.94) |
| Year 2 | 56 | 2.62 (2.44–2.82) | 2.34–3.10 | 9.8 | 142 | 2.99 (2.89–3.09) | 2.82–3.31 | 4.0 | 0.88 (0.81–0.95) |
| Year 3 | 51 | 2.81 (2.67–2.96) | 2.60–3.11 | 7.2 | 119 | 2.98 (2.90–3.07) | 2.84–3.31 | −0.2 | 0.94 (0.89–1.00) |
| Year 4 | 123 | 2.76 (2.62–2.90) | 2.65–3.13 | −1.9 | 191 | 3.02 (2.97–3.07) | 2.87–3.26 | 1.2 | 0.91 (0.87–0.96) |
| Year 7 | 162 | 2.76 (2.66–2.86) | 2.54–3.15 | 0.1 | 225 | 3.07 (3.01–3.13) | 2.94–3.40 | 1.8 | 0.90 (0.86–0.94) |
| Year 9 | 125 | 2.73 (2.55–2.92) | 2.58–3.16 | −1.1 | 136 | 3.05 (2.98–3.12) | 2.96–3.32 | −0.8 | 0.90 (0.83–0.96) |
| Year 11 | 178 | 2.70 (2.60–2.80) | 2.46–3.08 | −1.2 | 141 | 3.02 (2.94–3.11) | 2.89–3.32 | −0.8 | 0.89 (0.85–0.93) |
| p-for-trend* | 0.28 | 0.85 | |||||||
N total number of samples, n number of samples tested per study visit, GMA Geometric Mean of the Avidity Index, IQR interquartile range, CI confidence intervals, N/A not applicable.
†% change was calculated based on two consecutive visits.
*p-for-trend within dose group, over time in years 4–11.