Table 4.

Thrombocytopenic events for second dose ChAdOx1 vaccine.

Time-period post vaccination	Number of events	Number of person days	Incidence rate ratio (95% confidence interval)
Thrombocytopenia
Baseline	1786	929,694	1.0
Clearance	42	26,600	0.55 (0.16–1.79)
0–6 days	45	13,294	1.53 (0.54–4.35)
7–13 days	41	13,277	1.60 (0.57–4.53)
14–20 days	42	13,196	1.56 (0.57–4.49)
21–27 days	47	13,149	1.18 (0.36–3.84)
0–27 days	175	52,916	1.47 (0.59–3.63)
idiopathic thrombocytopenic purpura (ITP)
Baseline	147	74,788	1.0
Clearance	≤5	2164	0.67 (0.22–3.69)
0–6 days	≤5	1085	0.90 (0.34–2.54)
7–13 days	≤5	1063	1.37 (0.43–4.41)
14–20 days	6	1054	2.74 (0.89–6.54)
21–27 days	≤5	1037	0.49 (0.07–3.53)
0–27 days	18	4239	1.38 (0.73–2.61)