Table 1. Demographic and Clinical Characteristics of the Participants in the Phase 2–3 Trial.*.
| Characteristic | Children 6 Mo to <2 Yr of Age | Children 2 to 4 Yr of Age | ||||
|---|---|---|---|---|---|---|
| BNT162b2 (N=1178) |
Placebo (N=598) |
Total (N=1776) |
BNT162b2 (N=1835) |
Placebo (N=915) |
Total (N=2750) |
|
| Age at vaccination | ||||||
| Mean | 15.2±5.0 mo | 15.4±5.1 mo | 15.3±5.0 mo | 3.0±0.8 yr | 3.0±0.8 yr | 3.0±0.8 yr |
| Median (range) | 16.0 mo (6–23) | 16.0 mo (6–23) | 16.0 mo (6–23) | 3.0 yr (2–4) | 3.0 yr (2–4) | 3.0 yr (2–4) |
| Male sex — no. (%) | 589 (50.0) | 291 (48.7) | 880 (49.5) | 901 (49.1) | 471 (51.5) | 1372 (49.9) |
| Race or ethnic group — no. (%)† | ||||||
| White | 922 (78.3) | 480 (80.3) | 1402 (78.9) | 1469 (80.1) | 720 (78.7) | 2189 (79.6) |
| Black | 42 (3.6) | 24 (4.0) | 66 (3.7) | 94 (5.1) | 41 (4.5) | 135 (4.9) |
| American Indian or Alaska Native | 3 (0.3) | 1 (0.2) | 4 (0.2) | 3 (0.2) | 4 (0.4) | 7 (0.3) |
| Asian | 91 (7.7) | 40 (6.7) | 131 (7.4) | 127 (6.9) | 76 (8.3) | 203 (7.4) |
| Native Hawaiian or other Pacific Islander | 0 | 0 | 0 | 2 (0.1) | 1 (0.1) | 3 (0.1) |
| Multiracial | 117 (9.9) | 49 (8.2) | 166 (9.3) | 131 (7.1) | 69 (7.5) | 200 (7.3) |
| Not reported | 3 (0.3) | 4 (0.7) | 7 (0.4) | 9 (0.5) | 4 (0.4) | 13 (0.5) |
| Hispanic or Latinx ethnic group — no. (%)† | ||||||
| Yes | 161 (13.7) | 64 (10.7) | 225 (12.7) | 264 (14.4) | 120 (13.1) | 384 (14.0) |
| No | 1014 (86.1) | 530 (88.6) | 1544 (86.9) | 1568 (85.4) | 795 (86.9) | 2363 (85.9) |
| Not reported‡ | — | — | 7 (0.4) | — | — | 3 (0.1) |
| Country — no. (%) | ||||||
| Brazil‡ | — | — | 2 (0.1) | 0 | 0 | 0 |
| Finland | 54 (4.6) | 26 (4.3) | 80 (4.5) | 63 (3.4) | 30 (3.3) | 93 (3.4) |
| Poland | 125 (10.6) | 63 (10.5) | 188 (10.6) | 205 (11.2) | 103 (11.3) | 308 (11.2) |
| Spain | 42 (3.6) | 22 (3.7) | 64 (3.6) | 73 (4.0) | 35 (3.8) | 108 (3.9) |
| United States | 957 (81.2) | 485 (81.1) | 1442 (81.2) | 1494 (81.4) | 747 (81.6) | 2241 (81.5) |
| Baseline SARS-CoV-2 infection status — no. (%)§ | ||||||
| Positive | 89 (7.6) | 44 (7.4) | 133 (7.5) | 233 (12.7) | 125 (13.7) | 358 (13.0) |
| Negative | 1078 (91.5) | 541 (90.5) | 1619 (91.2) | 1597 (87.0) | 783 (85.6) | 2380 (86.5) |
| Missing data | 11 (0.9) | 13 (2.2) | 24 (1.4) | 5 (0.3) | 7 (0.8) | 12 (0.4) |
| Obesity — no. (%)¶ | ||||||
| Yes | — | — | — | 120 (6.5) | 45 (4.9) | 165 (6.0) |
| No | — | — | — | 1712 (93.3) | 870 (95.1) | 2582 (93.9) |
| Missing data‡ | — | — | — | — | — | 3 (0.1) |
| Coexisting conditions — no. (%)‖ | ||||||
| Yes | 50 (4.2) | 34 (5.7) | 84 (4.7) | 222 (12.1) | 130 (14.2) | 352 (12.8) |
| No | 1128 (95.8) | 564 (94.3) | 1692 (95.3) | 1613 (87.9) | 785 (85.8) | 2398 (87.2) |
| Time between dose 2 and dose 3 — no. (%) | ||||||
| <8 wk | 0 | 0 | 0 | 2 (0.1) | 2 (0.2) | 4 (0.1) |
| 8–12 wk | 145 (12.3) | 76 (12.7) | 221 (12.4) | 405 (22.1) | 184 (20.1) | 589 (21.4) |
| 13–16 wk | 51 (4.3) | 27 (4.5) | 78 (4.4) | 89 (4.9) | 37 (4.0) | 126 (4.6) |
| 17–20 wk | 54 (4.6) | 21 (3.5) | 75 (4.2) | 21 (1.1) | 13 (1.4) | 34 (1.2) |
| 21–24 wk | 53 (4.5) | 33 (5.5) | 86 (4.8) | 45 (2.5) | 19 (2.1) | 64 (2.3) |
| 25–28 wk | 246 (20.9) | 24 (4.0) | 270 (15.2) | 215 (11.7) | 21 (2.3) | 236 (8.6) |
| 29–32 wk | 129 (11.0) | 2 (0.3) | 131 (7.4) | 169 (9.2) | 4 (0.4) | 173 (6.3) |
| 33–44 wk‡ | — | — | 81 (4.6) | — | — | 95 (3.5) |
Plus–minus values are means ±SD. Results are shown for the safety population (children who received at least one dose of BNT162b2 or placebo). Percentages may not total 100 because of rounding.
Race and ethnic group were reported by the parents or guardians.
Because of blinding, only the values for the total population are shown.
A positive status for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) required a positive N-binding antibody test at the first vaccination visit, a positive nucleic acid amplification test at the first vaccination visit, or a medical history of coronavirus disease 2019 (Covid-19).
Obesity is defined for children 2 to 4 years of age as a body-mass index (the weight in kilograms divided by the square of the height in meters) at or above the 95th percentile according to the Centers for Disease Control and Prevention growth charts (https://www.cdc.gov/growthcharts/html_charts/bmiagerev.htm). Obesity is not defined for children younger than 2 years of age.
Coexisting conditions are those that increase the risk of severe Covid-19 (i.e., one or more prespecified underlying conditions defined by Kim et al.16). The most common medical history associated with increased risk of severe Covid-19 were obesity (2 to 4 years of age, 6.0%), asthma (6 months to <2 years of age, 0.8%; 2 to 4 years of age, 3.5%), and premature birth (6 months to <2 years of age, 1.7%; 2 to 4 years of age, 1.1%).