Table 1.
Demographic characteristics of participants in the study
| Total N | All |
AZ |
Pfizer short |
Pfizer long |
pa value |
|---|---|---|---|---|---|
| 684 | 92 | 84 | 508 | NT | |
| Dosing intervals | |||||
| Median days | 71 | 74 | 24 | 71 | NT |
| Median weeks | 10 | 11 | 3 | 10 | NT |
| IQR (days) | 63–77 | 64.75–78 | 21–27 | 66–78 | NT |
| Maximum days | 158 | 158 | 38 | 120 | NT |
| Minimum days | 14 | 53 | 0 | 0 | NT |
| Range (days) | 14–158 | 53:158 | 0:38 | 0:120 | NT |
| Infection status | |||||
| Naive, N (%) | 342 (50.0) | 45 (51.1) | 49 (41.7) | 248 (52.4) | NT |
| Total previous SARS-CoV-2, N (%) | 342 (50.0) | 47 (48.9) | 35 (58.3) | 266 (48.8) | 0.22 |
| Previous infection at baseline, Nb | 269 | 39 | 30 | 200 | NT |
| PCR + breakthrough infections, Nc | 33 | 5 | 4 | 24 | NT |
| Seroconverted during study, Nd | 49 | 6 | 1 | 42 | NT |
| Age | |||||
| Maximum age (years) | 77 | 77 | 71 | 71 | NT |
| Minimum age (years) | 22 | 22 | 22 | 22 | NT |
| Age range (years) | 22–77 | 22–77 | 22–71 | 22–71 | NT |
| Median age (years) | 43 | 43 | 45 | 43 | NT |
| Interquartile age range (years) | 33–52.3 | 27–56 | 37–55 | 33–51.25 | NT |
| Sex | |||||
| Female, N (%) | 505 (73.8) | 68 (73.9) | 50 (59.5) | 387 (76.2) | NT |
| Male, N (%) | 179 (26.2) | 24 (26.1) | 34 (40.5) | 121 (23.8) | 0.006 |
| Ethnicity | |||||
| White, N (%)e | 464 (83.8) | 71 (79.8) | 56 (84.8) | 337 (84.5) | NT |
| Asian, N (%)e | 56 (10.1) | 12 (13.5) | 5 (7.6) | 39 (9.8) | NT |
| Black, N (%)e | 7 (1.3) | 0 (0.0) | 1 (1.5) | 6 (1.5) | NT |
| Other, N (%)e | 27 (4.9) | 6 (6.7) | 4 (6.1) | 17 (4.3) | NT |
| Unreported, N | 130 | 3 | 18 | 109 | NT |
NT, not tested.
a
Differences between the groups were assessed using the chi-square test.
b
Previous infection at baseline (time of first vaccination) = previous PCR + SARS-CoV-2 +/− anti-nucleocapsid IgG positive at baseline.
c
PCR + breakthrough infections include nine re-infections that were in the “previous infection at baseline” group.
d
Seroconverted during study = no documented PCR+, lateral flow test, or suspected SARS-CoV-2 infection but asymptomatic rise in anti-nucleocapsid IgG (MSD) above assay positivity threshold and >2× baseline.
e
Percentage using total reported ethnicities as the denominator.