Table 5.
Meta-regression analysis of factors associated with VE against SARS-CoV-2 infection
| Factors | ba | 95% CI | P | S.E | Exp(b) | 95% CI |
|---|---|---|---|---|---|---|
| Study regionb | ||||||
| Western Pacific Region | Ref | – | – | – | 1 | – |
| Region of Americas | − 0.110 | (− 0.540, 0.320) | 0.610 | 0.214 | 0.896 | (0.583, 1.377) |
| European region | − 0.002 | (− 0.494, 0.490) | 0.993 | 0.245 | 0.998 | (0.610, 1.632) |
| Region of South-East Asia | − 0.041 | (− 0.673, 0.592) | 0.898 | 0.315 | 0.960 | (0.510, 1.808) |
| Eastern Mediterranean region | − 0.828 | (− 1.480, − 0.175) | 0.014 | 0.325 | 0.437 | (0.228, 0.839) |
| VOC | ||||||
| Alpha | Ref | – | – | – | 1 | – |
| Gamma | 0.759 | (− 0.210, 1.727) | 0.122 | 0.483 | 2.136 | (0.811, 5.626) |
| Delta | 0.413 | (− 0.417, 1.244) | 0.323 | 0.414 | 1.512 | (0.659, 3.469) |
| Omicron | 1.086 | (0.169, 2.004) | 0.021 | 0.457 | 2.963 | (1.184, 7.416) |
| Othersc | 0.543 | (− 0.364, 1.451) | 0.235 | 0.453 | 1.722 | (0.695, 4.269) |
| Time since vaccination | ||||||
| 14–90 | Ref | – | – | – | 1 | – |
| 91–180 | 0.533 | (− 0.039, 1.106) | 0.067 | 0.176 | 1.704 | (0.961, 3.021) |
| > 180 | 0.572 | (0.085, 1.059) | 0.022 | 0.285 | 1.772 | (1.089, 2.885) |
| Othersd | 0.158 | (− 0.194, 0.510) | 0.372 | 0.243 | 1.171 | (0.824, 1.666) |
| Constant | − 1.370 | (− 2.258, − 0.481) | 0.003 | 0.443 | 0.254 | (0.105, 0.618) |
S.E Standard error, Exp(b) Exponentiation of b, ref Reference group
aRegression coefficient
bCountries included in each region: Western Pacific Region includes China (Mainland and Hong Kong) and Malaysia; region of Americas includes Argentina, Brazil, Chile, Mexico, and Peru; European region includes Hungary, Kazakhstan, Serbia, and Turkey; region of South-East Asia includes Thailand and Indonesia; Eastern Mediterranean region includes Egypt, Iran, and Pakistan
cMixed, no VOC or unspecified predominant variant
dMixed, at least 14 days after vaccination and time interval cross groups or not extractable