Table 3.
Differences in Response Rate for Neutralizing Antibodies Between Primary 2-Dose and Booster Groups at Delivery
| Lab Assessment | Sample | PrimaryResponse Rate* | BoosterResponse Rate* | Prevalence Ratio**(95% CI) | p-value |
|---|---|---|---|---|---|
| D614G live virus nAb | Maternal Delivery | 79.0% (132/167) | 100% (73/73) | 1.10 (1.03, 1.18) | 0.0039 |
| Cord Blood | 93.5% (159/170) | 100% (75/75) | 1.04 (1.00, 1.09) | 0.0553 | |
| Delta live virus nAb | Maternal Delivery | 56.3% (94/167) | 100% (73/73) | 1.46 (1.28, 1.68) | <0.0001 |
| Cord Blood | 71.8% (122/170) | 100% (75/75) | 1.22 (1.11, 1.33) | <0.0001 | |
| Omicron live virus nAb | Maternal Delivery | 14.4% (24/167) | 72.6% (53/73) | 3.16 (2.13, 4.71) | <0.0001 |
| Cord Blood | 17.1% (29/170) | 88.0% (66/75) | 3.71 (2.53, 5.44) | <0.0001 | |
| Pseudotyped WT nAb | Maternal Delivery | 92.8% (155/167) | 100% (73/73) | 1.05 (1.01, 1.09) | 0.0138 |
| Cord Blood | 100% (169/169) | 100% (75/75) | 1.00 (1.00, 1.00) | n/a |
*
Response rate defined as number of samples above the lower limit of detection divided by number of samples tested.
**
From robust Poisson 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.