COVID-19 Articles
Open Access
Review

Table 3

Meta-analysis for SI of three variants of concern and their summary statistics.

Variant Number of SI estimates Mean 95% CI I 2 Cochran’s Q Egger
Alpha 75 5.17 4.87 – 5.47 97.10 2026* 0.58
Delta 8 4.07 3.03 – 5.10 99.10 700* < 0.0001
Omicron 7 3.06 2.76 – 3.37 83.04 30.88* 0.22

*P-value < 0.0001. SI: Serial interval; 95% CI: 95% confidence interval; I2: I-square or index of heterogeneity statistic; Cochran’s Q: Cochran’s Q heterogeneity statistic; Egger: Egger’s test for publication bias.