Table 5.

Incidence of ITP exacerbation^* after sample stratification by history of splenectomy and number of prior medical therapies or history of rituximab use

	First vaccine dose			Second vaccine dose
	n	ITP exacerbation (n)	ITP exacerbation (%)	n	ITP exacerbation (n)	ITP exacerbation (%)
Splenectomy, 0-4 prior therapies	7	2	28.6	6	1	16.7
Splenectomy, ≥5 prior therapies	10	6	60	9	4	44.4
No splenectomy, 0-4 prior therapies	47	1	2.1	37	6	16.2
No splenectomy, ≥5 prior therapies	6	3	50	3	1	33.3
Splenectomy, no prior rituximab	6	3	50	5	2	40
Splenectomy + prior rituximab	17	8	47.1	13	5	38.5
No splenectomy, no prior rituximab	50	3	6	28	3	10.7
No splenectomy + prior rituximab	22	2	9.1	14	4	28.6

^*Defined as development of any 1 or more of the following: (a) ≥50% decline in platelet count from prevaccination baseline; (b) >20% decline from prevaccination baseline and platelet nadir <30 ×10⁹/L; and/or (c) receipt of rescue therapy for ITP.