Table 2.
Differences in Antibody Levels Between Primary 2-Dose and Booster Groups at Delivery
| Lab Assessment | Sample | Primary GMT(95% CI) | BoosterGMT(95% CI) | Mean Log10Difference*(95% CI) | p-value |
|---|---|---|---|---|---|
| Spike IgG BAU/mL | Maternal Delivery | 313.8(260.7, 377.8) | 2200.6(1764.9, 2743.8) | 0.55(0.42, 0.68) | <0.0001 |
| Cord Blood | 500.5(424.1, 590.7) | 3290.4(2713.6, 3989.9) | 0.57(0.45, 0.69) | <0.0001 | |
| RBD IgG BAU/mL | Maternal Delivery | 428.6(351.9, 522.1) | 3382.9(2703.7, 4232.86) | 0.59(0.45, 0.73) | <0.0001 |
| Cord Blood | 673.1(564.5, 802.6) | 5005.7(4126.5, 6072.1) | 0.62(0.49, 0.75) | <0.0001 | |
| D614G live virus nAb ID50 | Maternal Delivery | 83.4(65.4, 106.4) | 446.4(342.1, 582.5) | 0.43(0.26, 0.60) | <0.0001 |
| Cord Blood | 96.4(80.2, 115.9) | 742.5(588.5, 936.8) | 0.65(0.52, 0.79) | <0.0001 | |
| Delta live virus nAb ID50 | Maternal Delivery | 39.0(30.9, 49.2) | 390.2(299.2, 508.9) | 0.73(0.57, 0.89) | <0.0001 |
| Cord Blood | 52.1(42.3, 64.2) | 644.5(507.5, 818.4) | 0.84(0.69, 0.99) | <0.0001 | |
| Omicron live virus nAb ID50 | Maternal Delivery | 13.5(11.9, 15.3) | 60.2(43.6, 83.1) | 0.52(0.39, 0.64) | <0.0001 |
| Cord Blood | 13.8(12.2, 15.6) | 109.2(81.6, 146.1) | 0.79(0.67, 0.91) | <0.0001 | |
| Pseudotyped WT nAb IC50 | Maternal Delivery | 93.4(77.3, 112.9) | 512.5(399.1, 658.3) | 0.52(0.36, 0.67) | <0.0001 |
| CordBlood | 220.8(183.5, 265.7) | 941.4(735.7, 1204.7) | 0.42(0.27, 0.57) | <0.0001 |
*
From regression analysis adjusted for days since last vaccination prior to delivery and prior self-reported SARS-CoV-2 infection or N protein positive at delivery.