Table 3.
Difference in antibody titers and QuantiFERON results in participants with suspected breakthrough infections compared to the other participants.
| Participants with suspected breakthrough infection (N = 6) |
Other participantsa (N = 602) |
P valueb | |
|---|---|---|---|
| Age, years (median, IQR) | 44.5 (30–47.75) | 45 (36–53) | 0.38 |
| Sex | |||
| Male (%) | 0 (0) | 170 (28.2) | 0.19 |
| Female (%) | 6 (1 0 0) | 432 (71.8) | |
| Antibody titer 3 months after vaccination (median, IQR) | |||
| Alinity RBD-IgG, AU/mL | 3758.3 (2396.4–5162.2) | 2740.0 (1780.8–4231.3) | 0.23 |
| HISCL S-IgG, SU/mL | 124.6 (72.3–146.5) | 92.0 (61.8–132.1) | 0.32 |
| STACIA Neut-Ab, U/mL | 8.8 (6.1–10.1) | 6.2 (4.3–8.6) | 0.12 |
| Antibody titer 6 months after vaccination (median, IQR) | |||
| Alinity RBD-IgG, AU/mL | 32407.1 (18973.3–76786.0) | 885.8 (573.1–1466.3) | <0.01 |
| HISCL S-IgG, SU/mL | 1590.6 (860.7–2720.3) | 37.0 (22.5–59.8) | <0.01 |
| STACIA Neut-Ab, U/mL | 51.2 (36.8–53.4) | 2.3 (1.6–3.5) | <0.01 |
| QuantiFERON SARS-CoV-2 results 8 weeks after vaccination (median, IQR) | |||
| IFN for Ag1, IU/mL | 0.16 (0.06–0.80) | 0.35 (0.14–0.80) | 0.35 |
| IFN for Ag2, IU/mL | 0.27 (0.10–1.13) | 0.62 (0.26–1.32) | 0.23 |
| QuantiFERON SARS-CoV-2 results 6 months after vaccination (median, IQR) | |||
| IFN for Ag1, IU/mL | 0.15 (0.07–0.73) | 0.15 (0.06–0.40) | 0.96 |
| IFN for Ag2, IU/mL | 0.18 (0.05–0.83) | 0.26 (0.10–0.69) | 0.48 |
Ag, antigen; IFN, interferon; IQR, interquartile range; Neut-Ab, neutralization antibody test; RBD-IgG, receptor-binding domain immunoglobulin G; S-IgG, anti-spike protein immunoglobulin G; SARS-CoV-2, severe acute respiratory syndrome coronavirus.
a
Participants who did not provide samples at both timepoints were excluded.
b
Fisher exact tests were used for categorical values, and Mann-Whitney U tests were used for continuous values.