Table 3:

Expected and observed rates of myocarditis with observed-to-expected ratios within a 21-day risk window after SARS-CoV-2 vaccination

Observed*ExpectedOE ratio (95% CI)
No. of casesNo. of vaccine dosesRate per 100 000 (95% CI)No. of casesPopulationRate per 100 000 (95% CI)
Overall14110 255 3851.37 (1.16–1.62)20.15 090 9550.39 (0.26–0.63)7.03 (5.92–8.29)
Sex
 Male1054 891 0112.15 (1.76–2.60)7.12 571 7790.28 (0.13–0.61)14.76 (12.07–17.87)
 Female365 364 3740.67 (0.47–0.93)13.22 519 1760.53 (0.30–0.93)2.72 (1.91–3.77)
Age, yr
 12–1719644 7052.95 (1.77–4.60)0.7300 5730.25 (0.01–1.85)25.66 (15.45–40.07)
 18–29531 784 9502.97 (2.22–3.88)5.4822 0280.65 (0.27–1.59)9.87 (7.39–12.9)
 30–39281 624 1331.72 (1.15–2.49)4.5721 0550.63 (0.23–1.62)6.17 (4.10–8.92)
 40–4971 340 7460.52 (0.21–1.08)2.6647 7310.40 (0.10–1.35)2.67 (1.07–5.50)
 50–59111 420 6910.77 (0.39–1.39)2.3725 4120.31 (0.09–1.21)4.88 (2.44–8.73)
 60–69111 552 2750.71 (0.35–1.27)2.3660 6850.35 (0.09–1.33)4.79 (2.39–8.56)
 70–7951 228 1620.41 (0.13–0.95)3.2413 8880.78 (0.26–2.47)1.54 (0.50–3.60)
 ≥ 807659 7231.06 (0.43–2.19)1.0229 2600.43 (0.01–2.43)7.05 (2.83–14.52)
Vaccine
 Pfizer846 989 9211.20 (0.96–1.49)13.75 090 9550.27 (0.15–0.46)6.15 (4.90–7.61)
 Moderna573 265 4641.75 (1.32–2.26)6.45 090 9550.13 (0.06–0.28)8.93 (6.76–11.57)
Dose
 Dose 1263 994 3800.65 (0.43–0.95)7.85 090 9550.15 (0.07–0.31)3.33 (2.17–4.88)
 Dose 2883 884 9872.27 (1.82–2.79)7.65 090 9550.15 (0.07–0.31)11.59 (9.29–14.27)
 Dose 3272 376 0181.14 (0.75–1.65)4.65 090 9550.09 (0.03–0.23)5.81 (3.83–8.46)
  • Note: CI = confidence interval, Moderna = mRNA-1273 (Moderna), OE = observed-to-expected, Pfizer = BNT162b2 (Pfizer-BioNTech).

  • * Myocarditis cases recorded within 21 days postvaccination between Dec. 15, 2020, and Mar. 31, 2022.

  • The background rates from 2019 were used to calculate the expected numbers.