Comparison 21. Safety: bacterial or viral infections, immune overload.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
21.1 Self‐controlled case series ‐ lobar pneumonia	2		Rate Ratio (IV, Fixed, 95% CI)	Subtotals only
21.1.1 Lobar pneumonia risk period (0 to 30 days)	2		Rate Ratio (IV, Fixed, 95% CI)	0.68 [0.53, 0.87]
21.1.2 Lobar pneumonia risk period (31 to 60 days)	2		Rate Ratio (IV, Fixed, 95% CI)	0.80 [0.63, 1.01]
21.1.3 Lobar pneumonia risk period (61 to 90 days)	2		Rate Ratio (IV, Fixed, 95% CI)	0.81 [0.64, 1.03]
21.1.4 Lobar pneumonia risk period (0 to 90 days)	2		Rate Ratio (IV, Fixed, 95% CI)	0.75 [0.64, 0.89]
21.2 Self‐controlled case series ‐ invasive bacterial infections	2		Rate Ratio (IV, Fixed, 95% CI)	Subtotals only
21.2.1 Invasive bacterial infections risk period (0 to 30 days)	2		Rate Ratio (IV, Fixed, 95% CI)	0.81 [0.58, 1.13]
21.2.2 Invasive bacterial infections risk period (31 to 60 days)	2		Rate Ratio (IV, Fixed, 95% CI)	1.07 [0.77, 1.48]
21.2.3 Invasive bacterial infections risk period (61 to 90 days)	2		Rate Ratio (IV, Fixed, 95% CI)	0.85 [0.58, 1.23]
21.2.4 Invasive bacterial infections risk period (0 to 90 days)	2		Rate Ratio (IV, Fixed, 95% CI)	0.90 [0.71, 1.13]
21.3 Self‐controlled case series ‐ encephalitis meningitis	1		Rate Ratio (IV, Fixed, 95% CI)	Subtotals only
21.3.1 Encephalitis ‐ meningitis risk period (0 to 30 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.54 [0.06, 4.84]
21.3.2 Encephalitis ‐ meningitis risk period (31 to 60 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.74 [0.07, 7.64]
21.3.3 Encephalitis ‐ meningitis risk period (61 to 90 days)	1		Rate Ratio (IV, Fixed, 95% CI)	1.46 [0.23, 9.28]
21.3.4 Encephalitis ‐ meningitis risk period (0 to 90 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.84 [0.20, 3.51]
21.4 Self‐controlled case series ‐ herpes	1		Rate Ratio (IV, Fixed, 95% CI)	Subtotals only
21.4.1 Herpes risk period (0 to 30 days)	1		Rate Ratio (IV, Fixed, 95% CI)	1.00 [0.57, 1.75]
21.4.2 Herpes risk period (31 to 60 days)	1		Rate Ratio (IV, Fixed, 95% CI)	1.69 [1.06, 2.70]
21.4.3 Herpes risk period (61 to 90 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.89 [0.50, 1.59]
21.4.4 Herpes risk period (0 to 90 days)	1		Rate Ratio (IV, Fixed, 95% CI)	1.17 [0.56, 2.46]
21.5 Self‐controlled case series ‐ pneumonia	1		Rate Ratio (IV, Fixed, 95% CI)	Subtotals only
21.5.1 Pneumonia risk period (0 to 30 days)	1		Rate Ratio (IV, Fixed, 95% CI)	Not estimable
21.5.2 Pneumonia risk period (31 to 60 days)	1		Rate Ratio (IV, Fixed, 95% CI)	1.39 [0.49, 3.92]
21.5.3 Pneumonia risk period (61 to 90 days)	1		Rate Ratio (IV, Fixed, 95% CI)	1.27 [0.41, 3.94]
21.5.4 Pneumonia risk period (0 to 90 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.72 [0.32, 1.60]
21.6 Self‐controlled case series ‐ varicella zoster	1		Rate Ratio (IV, Fixed, 95% CI)	Subtotals only
21.6.1 Varicella zoster risk period (0 to 30 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.58 [0.34, 0.99]
21.6.2 Varicella zoster risk period (31 to 60 days)	1		Rate Ratio (IV, Fixed, 95% CI)	1.23 [0.81, 1.87]
21.6.3 Varicella zoster risk period (61 to 90 days)	1		Rate Ratio (IV, Fixed, 95% CI)	1.05 [0.66, 1.67]
21.6.4 Varicella zoster risk period (0 to 90 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.93 [0.68, 1.27]
21.7 Self‐controlled case series ‐ miscellaneous viral infections	1		Rate Ratio (IV, Fixed, 95% CI)	Subtotals only
21.7.1 Miscellaneous viral infections risk period (0 to 30 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.71 [0.37, 1.37]
21.7.2 Miscellaneous viral infections risk period (31 to 60 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.73 [0.42, 1.28]
21.7.3 Miscellaneous viral infections risk period (61 to 90 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.61 [0.29, 1.28]
21.7.4 Miscellaneous viral infections risk period (0 to 90 days)	1		Rate Ratio (IV, Fixed, 95% CI)	0.68 [0.43, 1.08]