Table 4.

The subgroup analysis of included published studies.

Analysis	No. of studies	Sample size	OR	95% CI	P
Brazil
Adverse events	2	460	0.92	0.82 to 1.03	0.15
Serious adverse event	1	179	0.97	0.25 to 3.75	0.96
China
Adverse events	2	368	0.79	0.61 to 1.02	0.07
Serious adverse event	2	368	0.33	0.04 to 2.69	0.3
Russia
Adverse events	1	314	0.97	0.64 to 1.47	0.89
Serious adverse event	1	314	0.33	0.01 to 8.12	0.5