Table 3 Pooled rates and 95% CI for headache onset after injection against SARS-CoV-2

All vaccines recipients, 1^st dose

84

22%

(18–27%)

270,544.2

(p < .01)

100%

All vaccines recipients, 2^nd dose

46

29%

(23–35%)

16,478.5

(p < .01)

100%

Placebo recipients, 1^st dose

21

10%

(6–13%)

2203.7

(p < .01)

99%

Placebo recipients, 2^nd dose

10

12%

(7–17%)

955.7

(p < .01)

99%

mRNA vaccine recipients, 1^st dose

43

22%

(17–27%)

84,389.3

(p < .01)

100%

Traditional vaccine recipients, 1^st dose

54

23%

(18–29%)

44,406.8

(p < .01)

100%

BNT162b2, 1^st dose

41

21%

(16–27%)

82,671.2

(p < .01)

100%

BNT162b2, 2^nd dose

26

30%

(23–38%)

6784.6

(p < .01)

100%

ChAdOx1, 1^st dose

19

53%

(39–66%)

29,819.7

(p < .01)

100%

ChAdOx1, 2^nd dose

3

29%

(11–51%)

5.4

(p = .07)

63%

mRNA-1273, 1^st dose

5

28%

(10–51%)

64.4

(p < .01)

94%

mRNA-1273, 2^nd dose

3

54%

(32–74%)

12.6

(p < .01)

84%

NVX-CoV2373, 1^st dose

3

25%

(24–26%)

1.5

(p = .46)

0%

NVX-CoV2373, 2^nd dose

3

31%

(18–47%)

80.9

(p < .01)

100%

PiCoVacc, 1^st dose

9

11%

(5–19%)

1283.8

(p < .01)

100%