Table 4.

Increased risk of post-mRNA vaccine myocarditis in a database analysis of mostly (96.4%) hospitalised patients in the USA from December 2020 to August 2021 [11]

	Expected background myocarditis cases per million doses (95% CI)	Myocarditis cases per million doses with BNT162b2 (95% CI)		Myocarditis cases per million doses with mRNA-1273 (95% CI)
		First dose [95.5 million doses]	Second dose [114.2 million doses]	First dose [66.2 million doses]	Second dose [78.2 million doses]
Male adolescents or men
Aged 12–15 yrs	0.53 (0.40–0.70)	7.06 (4.88–10.23)	70.73 (61.68–81.11)	Not approved during this analysis
Aged 16–17 yrs	1.34 (1.05–1.72)	7.26 (4.45–11.86)	105.86 (91.65–122.27)	Not approved during this analysis
Aged 18–24 yrs	1.76 (1.58–1.98)	3.82 (2.40–6.06)	52.43 (45.56–60.33)	10.73 (7.50–15.34)	56.31 (47.08–67.34)
Aged 25–29 yrs	1.45 (1.21–1.74)	1.74 (0.78–3.87)	17.28 (13.02–22.93)	4.88 (2.70–8.80)	24.18 (17.93–32.61)
Aged 30–39 yrs	0.63 (0.54–0.73)	0.54 (0.20–1.44)	7.10 (5.26–9.57)	3.00 (1.81–4.97)	7.93 (5.61–11.21)
Female adolescents or women
Aged 12–15 yrs	0.17 (0.11–0.29)	0.49 (0.12–1.98)	6.35 (4.05–9.96)	Not approved during this analysis
Aged 16–17 yrs	0.42 (0.27–0.66)	0.84 (0.21–3.37)	10.98 (7.16–16.84)	Not approved during this analysis
Aged 18–24 yrs	0.38 (0.30–0.49)	0.18 (0.03–1.31)	4.12 (2.60–6.54)	0.96 (0.31–2.96)	6.87 (4.27–11.05)
Aged 25–29 yrs	0.48 (0.35–0.65)	0.26 (0.04–1.84)	2.23 (1.07–4.69)	0.41 (0.06–2.94)	8.22 (5.03–13.41)
Aged 30–39 yrs	0.47 (0.39–0.57)	0.72 (0.32–1.60)	1.02 (0.49–2.14)	0.74 (0.28–1.98)	0.68 (0.22–2.10)

The defined vaccine-to-symptom interval was 7 d. The analysis included cases meeting the definition by the CDC for myocarditis, reported via VAERS

BNT162b2 Pfizer BioNTech BNT162b2 COVID-19 vaccine, IRR adjusted incidence rate ratio in post-vaccine vs unvaccinated periods, mRNA-1273 Moderna mRNA-1273 COVID-19 vaccine