TABLE 2.
Outcomes Among Vaccinees During the 1 Through 21 Day Risk Interval After Any Dose of COVID-19 mRNA Vaccine, Compared on the Same Calendar Day With Outcomes Among Vaccinated Individuals 22 to 42 Days After Their Most Recent Dose, June 18, 2022 Through March 18, 2023
| Outcomeb | Risk Interval | Vaccine Type | Events in Risk Interval | Events in Comparison Interval (22–42 d) | Crude/Adjusted Expected Countsa | Adjusted Rate Ratio (95% CI)c | 1-Sided P | Signald |
|---|---|---|---|---|---|---|---|---|
| Appendicitis | 1–21 d | Pfizer-BioNTech | 1 | 1 | 0.9/2.1 | 0.49 (0.01–26.53) | .91 | No |
| Moderna | 0 | 1 | 1.5/NE | 0.00 (0.00–12.67) | .40 | No | ||
| Bell’s Palsy | 1–21 d | Pfizer-BioNTech | 0 | 1 | 0.5/NE | 0.00 (0.00–38.00) | .67 | No |
| Moderna | 1 | 0 | 0.0/NE | NE (0.06-∞) | .49 | No | ||
| Encephalitis, myelitis, or encephalomyelitis | 1–21 d | Pfizer-BioNTech | — | — | — | — | — | — |
| Moderna | 1 | 0 | 0.0/NE | NE (0.02-∞) | .74 | No | ||
| Guillain-Barre syndrome | 1–21 d | Pfizer-BioNTech | — | — | — | — | — | — |
| Moderna | 0 | 1 | 0.7/NE | 0.00 (0.00–26.75) | .59 | No | ||
| Immune thrombocytopenia | 1–21 d | Pfizer-BioNTech | 0 | 1 | 1.0/NE | 0.00 (0.00–18.77) | .50 | No |
| Moderna | 1 | 1 | 0.8/0.9 | 1.14 (0.03–44.34) | .72 | No | ||
| Kawasaki disease | 1–21 d | Pfizer-BioNTech | 2 | 1 | 1.1/1.0 | 2.05 (0.15–60.69) | .49 | No |
| Moderna | 0 | 3 | 5.8/NE | 0.00 (0.00–1.09) | .06 | No | ||
| Pulmonary embolism | 1–21 d | Pfizer-BioNTech | 1 | 0 | 0.0/NE | NE (0.08-∞) | .41 | No |
| Moderna | — | — | — | — | — | — | ||
| Seizures | 0–7 d | Pfizer-BioNTech | 9 | 24 | 9.5/14.0 | 0.64 (0.25–1.51) | .89 | No |
| Moderna | 5 | 19 | 54/5.9 | 0.85 (0.27–2.32) | .70 | No | ||
| 0–21 d | Pfizer-BioNTech | 38 | 24 | 25.0/38.9 | 0.98 (0.56–1.71) | .59 | No | |
| Moderna | 23 | 19 | 20.9/21.0 | 1.09 (0.57–2.11) | .46 | No | ||
| Stroke, hemorrhagic | 1–21 d | Pfizer-BioNTech | 1 | 1 | 1.1/0.9 | 1.12 (0.03–44.64) | .72 | No |
| Moderna | — | — | — | — | — | — | ||
| Transverse myelitis | 1–21 d | Pfizer-BioNTech | — | — | — | — | — | — |
| Moderna | 0 | 1 | 0.5/NE | 0.00 (0.00–38.00) | .67 | No | ||
| Venous thromboembolism | 1–21 d | Pfizer-BioNTech | — | — | — | — | — | — |
| Moderna | 0 | 1 | 0.5/NE | 0.00 (0.00–38.00) | .67 | No |
NE, not estimable. —, analysis not yet possible.
Expected counts: crude estimate via indirect standardization and maximum likelihood estimate.
Outcomes were only included in this table if there were events in either the risk or comparison interval for either vaccine type after any dose, making analyses possible. All outcomes under surveillance are listed in Supplemental Table 3. Safety monitoring by individual dose is ongoing, however, since very few outcomes have cases in either the risk or comparison interval only combined analyses are presented here.
Stratified by Vaccine Safety Datalink site, age (year), sex, race and ethnicity, and calendar date.
Signal defined as 1-sided P < 0.011.