Table 2.
Clinical characteristics of individuals vaccinated with mRNA-1273 and their 1-to-1 propensity-matched unvaccinated cohorts
| Clinical covariate | mRNA-1273-vaccinated cohort | 1-to-1 propensity-matched unvaccinated cohort | Standardized mean difference (SMD) |
|---|---|---|---|
| Total number of individuals | 16,471 | 16,471 | |
| Age, mean (SD) | 63 (16.14) | 62.23 (16.72) | 0.05∗∗∗ |
| Age groups in years | |||
| 18–24 | 375 (2.3%) | 388 (2.4%) | 0.01∗∗∗ |
| 25–34 | 926 (5.6%) | 1,074 (6.5%) | 0.04∗∗∗ |
| 35–44 | 1,285 (7.8%) | 1,484 (9.0%) | 0.04∗∗∗ |
| 45–54 | 1,598 (9.7%) | 1,601 (9.7%) | 0.00∗∗∗ |
| 55–64 | 3,402 (20.7%) | 3,436 (20.9%) | 0.01∗∗∗ |
| 65–74 | 5,598 (34.0%) | 5,121 (31.1%) | 0.06∗∗∗ |
| 75+ | 3,287 (20.0%) | 3,367 (20.4%) | 0.01∗∗∗ |
| Sex | |||
| Female | 8,758 (53.2%) | 8,758 (53.2%) | 0.00∗∗∗ |
| Male | 7,713 (46.8%) | 7,713 (46.8%) | 0.00∗∗∗ |
| Unknown | 0 (0.0%) | 0 (0.0%) | N/A |
| Race | |||
| Asian | 378 (2.3%) | 463 (2.8%) | 0.03∗∗∗ |
| Black/African American | 530 (3.2%) | 437 (2.7%) | 0.03∗∗∗ |
| Native American | 44 (0.3%) | 30 (0.2%) | 0.02∗∗∗ |
| White/Caucasian | 15,088 (91.6%) | 15,141 (91.9%) | 0.01∗∗∗ |
| Other | 273 (1.7%) | 278 (1.7%) | 0.00∗∗∗ |
| Unknown | 158 (1.0%) | 122 (0.7%) | 0.02∗∗∗ |
| Ethnicity | |||
| Hispanic or Latino | 522 (3.2%) | 408 (2.5%) | 0.04∗∗∗ |
| Not Hispanic or Latino | 15,583 (94.6%) | 15,834 (96.1%) | 0.07∗∗∗ |
| Unknown | 366 (2.2%) | 229 (1.4%) | 0.06∗∗∗ |
| Mean number of prior SARS-CoV-2 PCR tests | |||
| February 1–May 30, 2020 | 0.2189 (0.5214) | 0.2168 (0.5282) | 0.00∗∗∗ |
| June 1–August 31, 2020 | 0.5114 (0.8292) | 0.4902 (0.8364) | 0.03∗∗∗ |
| September 1–November 30, 2020 | 0.5724 (0.8154) | 0.6195 (0.9051) | 0.05∗∗∗ |
| Mean number of prior influenza tests | |||
| February 1–May 30, 2020 | 0.266 (0.85) | 0.2498 (0.8491) | 0.02∗∗∗ |
| June 1–Aug 31, 2020 | 0.03967 (0.3932) | 0.03291 (0.4238) | 0.02∗∗∗ |
| September 1–November 30, 2020 | 0.08333 (0.5536) | 0.08354 (0.5692) | 0.02∗∗∗ |
| State | |||
| Arizona | 1,896 (11.5%) | 1,896 (11.5%) | 0.00∗∗∗ |
| Florida | 5,453 (33.1%) | 5,453 (33.1%) | 0.00∗∗∗ |
| Iowa | 64 (0.4%) | 64 (0.4%) | 0.00∗∗∗ |
| Minnesota | 6,299 (38.2%) | 6,299 (38.2%) | 0.00∗∗∗ |
| Wisconsin | 2,759 (16.8%) | 2,759 (16.8%) | 0.00∗∗∗ |
| Long-term care resident | 50 (0.3%) | 50 (0.3%) | 0.00∗∗∗ |
Covariates for matching include (1) demographics (age, sex, race, ethnicity); (2) number of prior SARS-CoV-2 PCR tests before December 1, 2020; (3) number of influenza tests between February 1 and December 1, 2020; (4) residential location (zip code); and (5) long-term care facility status. Sex, zip code, and long-term care status are matched exactly between the two cohorts, so the proportions of individuals with each feature in these categories are identical. Highly balanced covariates with SMD < 0.1 are indicated by ∗∗∗. See also Table S1.