Table 1. Characteristics of cases of myocarditis/pericarditis (n. 441) among the mRNA-vaccinated population aged 12–39 years from 27 December 2020 to 30 September 2021 by vaccine product.

	mRNA [n.(%)]	BNT162b2 [n.(%)]	mRNA-1273 [n.(%)]
Number of participants	441	346	95
Sex
Males	302 (68.5%)	232 (67.1%)	70 (73.7%)
Females	139 (31.5%)	114 (32.9%)	25 (26.3%)
Charlson index
≥1	53 (12.0%)	46 (13.3%)	7 (7.4%)
Hospitalizations in the last 2 years
≥1	188 (42.6%)	154 (44.5%)	34 (35.8%)
Comorbidities
COVID-19 diagnosis before vaccination	60 (13.6%)	48 (13.9%)	12 (12.6%)
COPD/Asthma	32 (7.3%)	28 (8.1%)	4 (4.2%)
Chronic pulmonary disease	16 (3.6%)	15 (4.3%)	1 (1.1%)
Chronic kidney failure	9 (2.0%)	7 (2.0%)	2 (2.1%)
Neoplasms	16 (3.6%)	14 (4.0%)	2 (2.1%)
Diabetes mellitus	8 (1.8%)	4 (1.2%)	4 (4.2%)
Hematologic disease	50 (11.3%)	43 (12.4%)	7 (7.4%)
Cardiovascular/cerebrovascular diseases	170 (38.5%)	138 (39.9%)	32 (33.7%)
Hypertension	82 (18.6%)	66 (19.1%)	16 (16.8%)
Hepatopathy	2 (0.5%)	1 (0.3%)	1 (1.1%)
HIV	2 (0.5%)	2 (0.6%)	0
Rheumatic diseases	23 (5.2%)	18 (5.2%)	5 (5.3%)
Cystic fibrosis	0	0	0
Neurological diseases	26 (5.9%)	20 (5.8%)	6 (6.3%)
Peptic ulcer	152 (34.5%)	122 (35.3%)	30 (31.6%)
Colitis	5 (1.1%)	4 (1.2%)	1 (1.1%)
Celiac disease	1 (0.2%)	1 (0.3%)	0
Infection	155 (35.1%)	125 (36.1%)	30 (31.6%)
Prior drugs use
Prescriptions in the last 12 months (1+)	307 (69.6%)	246 (71.1%)	61 (64.2%)
Corticosteroids for systemic use	57 (12.9%)	49 (14.2%)	8 (8.4%)
NSAIDs use	48 (10.9%)	40 (11.6%)	8 (8.4%)
Estroprogestinics use	2 (0.5%)	1 (0.3%)	1 (1.1%)

COPD, chronic obstructive pulmonary disease; HIV, human immunodeficiency virus; n., number; NSAID, nonsteroidal anti-inflammatory drug; yrs, years.