Table. SARS-CoV-2 nucleocapsid total immunoglobulin seroreversion by GAMM and half-life methods, by months from infection, among healthcare workers in Boston, Massachusetts, USA, 2020*.
| Months | GAMM, % (95% CI) | Half-life, % (95% CI) |
|---|---|---|
| 4 | 0 (0–4.9) | 0.6 (0.6–0.6) |
| 6 | 2.7 (3.0–9.5) | 1.2 (1.0–1.3) |
| 8 | 5.5 (1.5–13.4) | 2.1 (1.8–2.6) |
| 10 | 9.6 (3.9–18.8) | 3.8 (2.9- 4.8) |
| 12 | 11 (4.9–20.5) | 6.2 (4.7–8.3) |
| 14 | 12.3 (5.8–22.1) | 9.8 (7.2–13.3) |
| 16 | 13.7 (6.8–23.8) | 14.8 (10.6–20.1) |
| 18 | 15.1 (7.8–25.4) | 21.1 (15.0–28.7) |
| 24 | NC | 48.9 (36.1–62.1) |
*The GAMM method estimates are restricted to observational data and therefore not calculated more than 18 months postinfection. Half-life method represents constant log linear antibody contraction with an estimated peak total nucleocapsid antibody level that had a cutoff index of 37 and a half-life of 128 days. GAMM, generalized additive mixed model; NC, not calculated.