Table 2. SARS-CoV-2 spike binding antibody serostatus, geometric mean titers, and median titers of participants in study of SARS-CoV-2 spike antibody levels, by study period interval, Dominican Republic, March 2021–August 2022*.
| Study period interval | No. patients | Seropositive, no. (%)† | GMT (95% CI) | Median titer, BAU/mL (Q1—Q3) |
|---|---|---|---|---|
| Mar–Jun 2021 | 434 | 265 (61.1) | 6.6 (5.1–8.7) | 3.8 (0.4–57.5) |
| Jul–Sep 2021 | 397 | 344 (86.6) | 62.8 (45.8–86.0) | 62.5 (6.0–581.8) |
| Oct–Dec 2021 | 579 | 543 (93.8) | 559.4 (439.8–711.5) | 781.7 (104.9–4,813.5) |
| Jan–Apr 2022 | 463 | 434 (93.7) | 1,180.3 (906.3–1,537.2) | 2,578 (390.8–8,137.5) |
| May–Aug 2022 | 427 | 409 (95.8) | 1,332.4 (1,055.3–1,682.3) | 2,876 (775.8–5,483.5) |
*N = 2,300. Study periods indicate complete months except March 2021, which represents enrollment starting March 22, 2021, and August 2022, which represents enrollment through August 17, 2022. BAU, binding antibody units; GMT, geometric mean titer. †Seropositive defined as SARS-CoV-2 spike binding antibodies above the test manufacturer’s cutoff index (>0.8 BAU/mL).