Table 1.
Study Participant Characteristics by Group Assigned at Enrollment
| Maternal Characteristic | Pfizer-BioNTechn=100Median (IQR)% (n) | Modernan=67Median (IQR)% (n) | Boostern=73Median (IQR)% (n) |
|---|---|---|---|
| Age, years | 35 (31, 37) | 34 (31, 37) | 34 (31, 37) |
| RaceAsianBlack/African AmericanWhiteOther | 12.0 (12)10.0 (10)75.0 (75)3.0 (3) | 4.5 (3)16.4 (11)73.1 (49)6.0 (4) | 9.6 (7)1.4 (1)83.6 (61)5.5 (4) |
| Hispanic or Latino | 10.0 (10) | 14.9 (10) | 9.6 (7) |
| Vaccine Exposure up to Delivery2 doses Pfizer only2 doses Pfizer+Pfizer boost2 doses Pfizer+Moderna boost2 doses Moderna only2 doses Moderna+Moderna boost2 doses Moderna+Pfizer boost | 98.0 (98)2.0 (2)0.0 (0) | 92.5 (62)6.0 (4)1.5 (1) | 76.7 (56)16.4 (12)4.1 (3)2.7 (2) |
| Weeks Between Last Dose and Post-Vaccination Visit | 18.8 (14.6, 23.4) | 18.3 (12.9, 23.6) | 6.0 (3.3, 8.1) |
| Weeks Between Primary Series Completion and Delivery | 21.9 (18.0, 26.4) | 22.9 (18.3, 27.3) | 46.7 (40.4, 50.9) |
| Weeks Between Last Dose and Delivery | 21.6 (17.1, 25.7) | 21.9 (15.4, 24.6) | 10.4 (6.9, 14.1) |
| Gestational Age at First Dose During Pregnancy, weeks | 13.1 (9.3, 17.9) | 12.7 (7.6, 15.7) | -10.9 (-14.9, -4.6) |
| Gestational Age at Last Dose During Pregnancy, weeks | 16.9 (13.4, 21.3) | 17.1 (14.0, 23.7) | 28.6 (24.9, 31.7) |
| Gestational Age at Delivery, weeks | 39.3 (37.9, 40.1) | 39.1 (38.7, 39.9) | 39.1 (38.3, 39.6) |
| SARS-CoV-2 infection prior to or during study, up to delivery, self-reported OR N protein positive at delivery | 15.0 (15) | 13.4 (9) | 17.8 (13) |
| GravidityPrimigravidaAt least one prior pregnancyAt least two prior pregnancies | 30.0 (30)70.0 (70)32.0 (32) | 44.8 (30)55.2 (37)29.9 (20) | 42.5 (31)57.5 (42)28.8 (21) |
| Maternal obstetric comorbiditiesGestational diabetesHypertensive disordersObesityPre-eclampsia | 8.0 (8)10.0 (10)9.0 (9)0.0 (0) | 13.4 (9)9.0 (6)10.4 (7)0.0 (0) | 6.8 (5)13.7 (10)13.7 (10)2.7 (2) |
| Mode of deliveryC-sectionVaginal | 33.0 (33)67.0 (67) | 43.3 (29)56.7 (38) | 30.1 (22)69.9 (51) |
| Infant Characteristic | Pfizer-BioNTechn=102% (n) | Modernan=68% (n) | Boostern=75% (n) |
| Preterm birth (<37 weeks) | 6.9 (7) | 7.4 (5) | 14.7 (11) |
| Infant Birthweight (grams) | 3370 (3040, 3640) | 3340 (3030, 3560) | 3280 (2860, 3540) |