Table 2.
Model results of the meta-regression analysis performed with respect to the type of COVID-19 vaccine, the rate of confirmed COVID-19 cases, and the age and sex of recipients.
| Co-variate | Regression Coefficient, Mean and 95%CI | p Value | Modifying Factor |
|---|---|---|---|
| Vaccine type | |||
| Overall | −1.227 (−2.355–−0.099) | 0.033 | Yes |
| Sensitivity analysis by excluding AZD1222 | −0.430 (−1.149–0.289) | 0.241 | No |
| Rate of COVID-19 cases | 0.001 (−0.013–0.015) | 0.933 | No |
| Age | |||
| Overall | 0.014 (−0.008–0.036) | 0.215 | No |
| mRNA-based vaccines | 0.023 (−0.003–0.049) | 0.081 | No, but detected a trend toward significance |
| Adenovirus-based vaccines | −0.005 (−0.046–0.036) | 0.807 | No |
| Sex | −0.539 (−1.261–0.183) | 0.144 | No |
COVID-19: Coronavirus Disease 2019; mRNA: messenger ribonucleic acid; 95%CI: 95% confidence interval.