Table 4.
Comparison of COVID-19 antibody response between the participants who acquired COVID-19 infection (n = 29) or not (n = 106) after the second dose of vaccine (n = 135) in overall cohort.
| COVID-19 Antibody | Time of Specimen Collection (Days) | |||||||
|---|---|---|---|---|---|---|---|---|
| Before the Second Dose | 60 Days after Second Dose | 150 Days after Second Dose | 270 Days after Second Dose | |||||
| Acquired COVID-19 Infection | Not Acquired COVID-19 Infection | Acquired COVID-19 Infection | Not Acquired COVID-19 Infection | Acquired COVID-19 Infection | Not Acquired COVID-19 Infection | Acquired COVID-19 Infection | Not Acquired COVID-19 Infection | |
| Anti-Spike antibody (U/mL) | 76.8 (23.4–200.4) |
78.3 (19.3–684.9) |
14,019 (4546–25,000) |
316.7 (102.3–3447) |
2062 (139–4317) |
120.7 (50.9–1584) |
2185 (1414–4611) |
2052 (215.8–10,177) |
| p value | 0.362 | <0.001 | 0.002 | 0.306 | ||||
| Neutralising antibody (%) | 18 (7.6–27.5) |
24.5 (8.7–66.6) |
86.9 (66.6–97) |
27.3 (5.7–83.1) |
79.3 (45–90.8) |
24.6 (3.3–85) |
67.7 (54–84.7) |
50.3 (12.6–85.2) |
| p value | 0.071 | <0.001 | 0.007 | 0.206 | ||||
Anti-spike antibody titre is expressed as U/mL and neutralising antibody is expressed in percentage. The anti-spike antibody titre value ≥ 0.80 U/mL is considered positive. The specimens with calculated neutralisation ≥ 20% are considered positive for neutralising antibody. Data are expressed as median (inter quartile range).