Table 2.
Breakthrough infections among individuals with prior SARS-CoV-2 infections who received one dose or two doses of COVID vaccine (unadjusted).
| N | Infection rate | Hazard Ratio 95%CI (vs. two doses) | ||||
|---|---|---|---|---|---|---|
| Unvaccinated (n=94072) | One dose (n=52773) | Two doses (n=67000) | Unvaccinated | One dose | ||
| All | 213845 | 146.5 | 92.1 | 51.2 | 3.49(3.34–3.64) | 1.48(1.39–1.58) |
| Age | ||||||
| 18–44 | 79074 | 114.3 | 101.7 | 54.9 | 2.56(2.38–2.76) | 1.65(1.48–1.83) |
| 45–64 | 85546 | 148.2 | 92.8 | 48.7 | 3.71(3.45–3.97) | 1.63(1.48–1.80) |
| 65+ | 49225 | 206.5 | 79.6 | 51.3 | 4.91(4.49–5.36) | 1.11(0.98–1.26) |
| Sex | ||||||
| Female | 131463 | 143.6 | 96.5 | 54.6 | 3.21(3.04–3.39) | 1.44(1.33–1.56) |
| Male | 82382 | 150.9 | 85.6 | 45.8 | 4.01(3.72–4.32) | 1.57(1.42–1.74) |
| Race/Ethnicity | ||||||
| Hispanic | 20594 | 125.7 | 96.7 | 60.8 | 2.52(2.21–2.88) | 1.42(1.17–1.71) |
| Non-Hispanic White | 141856 | 141.2 | 82.5 | 47.0 | 3.67(3.47–3.89) | 1.47(1.36–1.59) |
| Non-Hispanic Black | 26499 | 168.3 | 95.3 | 64.0 | 3.32(2.96–3.71) | 1.32(1.11–1.56) |
| Other | 24896 | 179.4 | 131.5 | 52.9 | 4.00(3.53–4.54) | 1.80(1.54–2.10) |
| Vaccine type | ||||||
| Pfizer-BioNTech | 66612 | 97.8 | 55.5 | 1.78(1.63–1.93) | ||
| Other | 53161 | 86.2 | 47.1 | 1.98(1.80–2.18) | ||
Infection rate: per 1000 person in 6 months. The infection rate was defined as the number of new breakthrough infections during study follow up divided by the person-time at risk throughout that period (infection rate = no. of new breakthrough infections/total person-time at risk). The infection rate was unadjusted.