Table 1.

Reported cases of acquired hemophilia A that arose after the administration of mRNA COVID-19 vaccines.

Age	Sex	Time to onset from last dose	Vaccine	Diagnosis and	Symptomsa	Severityb	FVIII inhibitor	Immunosuppressive	Outcome	References
				treatment			(BU/mL)	treatment
69	M	9 days after 1st dose	N.A.	After 2nd dose	Hematoma in rectus femoris muscle	Mild	80	PSL	After 4 weeks, the inhibitor level had decreased to 2 BU/mL.	Radwi M et al. [6]
85	M	1 week after 1st dose	Moderna mRNA-1273	After 2nd dose	Hematoma in iliopsoas muscle	Severe	2.2	PSL, Rit	Died	Cittone MG et al. [12]
86	F	3 weeks after 2nd dose	Moderna mRNA-1273	After 2nd dose	Hemothorax	Severe	1.1	PSL	After 17 days, the FVIII:C level had increased to 178%.	Cittone MG et al. [12]
72	F	2 weeks after 1st dose	Moderna mRNA-1273	After 1st dose	Cutaneous hematomas, anemia	Severe	12.4	PSL, Rit	After 3 weeks, the inhibitor level had decreased to 5.6 BU/mL.	Cittone MG et al. [12]
76	F	4 days after 2nd dose	Moderna mRNA-1274	After 2nd dose	Ecchymoses, melanotic stool, anemia	Severe	11.2	mPSL, PSL	After 26 days, the inhibitor level had decreased to <0.5 BU/mL.	Portuguese AJ et al. [13]
67	M	19 days after 2nd dose	Pfizer BioNTech	After 2nd dose	Hematoma in the leg	Mild	110	PSL, Rit	After 34 days, the inhibitor level had decreased to <0.5 BU/mL.	Farley S et al. [14]
70	M	8 days after 1st dose	Moderna mRNA-1273	After 1st dose	Ecchymoses	Mild	39.9	PSL, CPA	After 6 days, the inhibitor level had decreased to 11.4 BU/mL.	Lemoine C et al. [15]
86	M	14 days after 2nd dose	Pfizer BioNTech	After 2nd dose	Hematoma, anemia	Severe	2.1	mPSL	After 7 months, the inhibitor became undetectable.	Leone MC et al. [16]
73	F	14 days after 1st dose	Pfizer BioNTech	After 2nd dose	Hematomas in knee and jaw	Mild	0.8	mPSL	After 5 months, the inhibitor became undetectable.	Leone MC et al. [16]
67	M	49 days after 2nd dose	Pfizer BioNTech	After 2nd dose	Hematoma of the tongue	Mild	2.5	PSL, CPA	Six days after discharge, the inhibitor became undetectable.	Leone MC et al. [16]
77	M	52 days after 2nd dose	Pfizer BioNTech	After 2nd dose	Hematuria, anemia	Severe	6.9	mPSL, Rit	Died	Leone MC et al. [16]
95	F	1 week after 1st dose	Pfizer BioNTech	After 2nd dose	Hematoma in hand	Mild	5.4	PSL, Rit	After 22 days, the inhibitor level had decreased to 0.7 BU/mL.	Murali A et al. [17]
39	F	10 days after 1st dose	Pfizer BioNTech	After 1st dose	Hematuria	Mild	17.2	None	After 2 months, the FVIII:C level had increased to 78.8%.	Soliman DS et al. [18]
80	M	2 weeks after 1st dose	Pfizer BioNTech	After 1st dose	Hematoma of the thigh, anemia	Severe	7.5	mPSL, PSL, AZ	After 6 weeks, the inhibitor became undetectable.	Ai Vuen L et al. [19]
75	M	3 months after 2nd dose	Pfizer BioNTech	After 2nd dose	Ecchymoses, anemia	Severe	318	PSL, Rit, CPA, CyA	Improved	Al Hennawi H et al. [20]
77	M	3 weeks after 2nd dose	Moderna mRNA-1273	After 2nd dose	Ecchymoses	Mild	71.6	PSL, CPA	After 5 weeks, the inhibitor level had decreased to 49 BU/mL.	Fu PA et al. [21]
72	M	9 days after 3rd dose	Moderna mRNA-1273	After 3rd dose	Ecchymoses, anemia	Severe	158.6	PSL, CPA, Rit	After 3 weeks, the inhibitor level had decreased to 20.6 BU/mL.	Plüß M et al. [22]
75	M	6 days after 3rd dose	Pfizer BioNTech	After 3rd dose	Ecchymoses, anemia	Severe	N.A.	PSL, CPA	After 12 days, the FVIII:C level had increased to a normal level.	Rashid A et al. [23]
45	F	2 weeks after 3rd dose	Moderna mRNA-1273	After 3rd dose	Subcutaneous hemorrhage	Mild	12.8	PSL	After 3 weeks, the inhibitor level had decreased to 0.1 BU/mL.	This case

COVID-19, coronavirus disease 2019; M, male; F, female; N.A., not applicable; FVIII, factor VIII; BU, Bethesda units; FVIII:C, FVIII coagulant activity.

PSL, prednisolone; Rit, rituximab; mPSL, methylprednisolone; CPA, cyclophosphamide; AZ, azathioprine; CyA, cyclosporine A.

^aAnemia was defined as a hemoglobin (Hb) level of <8 g/dL or a sudden drop in the Hb level of >2 g/dL that required a blood transfusion.

^bSymptom severity was classified according to previous reports [11,26].