Table 3.
Incidence rate ratios for SARS-CoV-2 infection in 64 PwMS according to antibody and T cell-specific immune response evaluated after 2–4 weeks from the booster dose.
| Immune Response | No BI | BI | Total | Univariable | Multivariable | ||||
|---|---|---|---|---|---|---|---|---|---|
| 36 (56.3) | 28 (43.8) | 64 (100) | IRR | 95%CI | p | aIRR | 95%CI | p | |
| anti-RBD IgG (BAU/mL) | |||||||||
| continuous, median (IQR) | 352 (24–5513) | 135 (1–1337) | 272 (8–4222) | ||||||
| score: Negative (<7.1) | 5 (13.9) | 11 (39.3) | 16 (25.0) | Ref. | Ref. | ||||
| score: Positive (≥7.1) | 31 (86.1) | 17 (60.7) | 48 (75.0) | 0.33 | 0.15–0.7 | 0.004 | 0.40 | 0.17–0.97 | 0.042 |
| IFN-γ T cell-specific response (pg/mL) | |||||||||
| continuous, median (IQR) | 30 (1–222) | 188 (1–578) | 79 (1–349) | ||||||
| <16 | 17 (47.2) | 10 (35.7) | 27 (42.2) | Ref. | Ref. | ||||
| ≥16 | 19 (52.8) | 18 (64.3) | 37 (57.8) | 1.61 | 0.74–3.49 | 0.228 | 0.55 | 0.22–1.34 | 0.187 |
| Neutralizing antibodies | |||||||||
| continuous, median (IQR) | 15 (5–320) | 5 (5–160) | 8 (5–320) | ||||||
| <10 | 17 (47.2) | 15 (53.6) | 32 (50.0) | Ref. | Ref. | ||||
| ≥10 | 19 (52.8) | 13 (46.4) | 32 (50.0) | 0.83 | 0.39–1.74 | 0.618 | 0.68 | 0.30–1.55 | 0.362 |
PwMS: patients with multiple sclerosis; RBD: receptor-binding domain; IFN: interferon; BI: breakthrough infection; IRR: incidence rate ratio estimated with Poisson regression; aIRR: IRR adjusted for EDSS score and phenotype; CI: confidence interval; Ref: reference category. In bold are reported the patient’s immunologic variables and the significant values.