. 2023 Jul 13;9(9):1221–1229. doi: 10.1001/jamaoncol.2023.2271

Table 3. Incidence and Risk of COVID-19 by Unvaccinated or Partially Vaccinated, Fully Vaccinated, and Boosted Populations.

Vaccine doses	COVID-19 incidence (95% CI)			COVID-19 hospitalization (95% CI)			COVID-19 severe disease (95% CI)
Vaccine doses	Active treatment	Cancer survivors	Controls	Active treatment	Cancer survivors	Controls	Active treatment	Cancer survivors	Controls
Delta wave
0 or 1 dose	0.64 (0.50-0.82)	0.92 (0.75-1.13)	0.28 (0.26-0.30)	1.57 (1.18-2.10)	2.80 (2.16-3.62)	0.99 (0.88-1.11)	3.37 (1.92-5.91)	9.37 (6.34-13.84)	2.51 (2.12-2.96)
2 doses	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]
3 doses	0.37 (0.29-0.48)	0.34 (0.29-0.40)	0.26 (0.25-0.28)	0.24 (0.15-0.38)	0.23 (0.16-0.33)	0.14 (0.11-0.17)	0.14 (0.03-0.59)	0.13 (0.05-0.33)	0.07 (0.05-0.12)
Omicron wave
0 or 1 dose	0.71 (0.59-0.87)	0.73 (0.63-0.85)	0.40 (0.37-0.44)	NA^a	NA^a	NA^a	1.85 (0.99-3.47)	1.56 (1.02-2.39)	0.82 (0.62-1.08)
2 doses	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]	1 [Reference]
3 doses	0.91 (0.86-0.97)	0.91 (0.86-0.96)	0.91 (0.88-0.93)	0.45 (0.40-0.52)	0.27 (0.24-0.32)	0.29 (0.27-0.32)	0.29 (0.20-0.42)	0.19 (0.14-0.26)	0.21 (0.18-0.25)
4 doses	0.78 (0.70-0.88)	0.80 (0.74-0.87)	0.85 (0.81-0.88)	0.24 (0.18-0.33)	0.15 (0.12-0.19)	0.21 (0.18-0.25)	0.13 (0.06-0.31)	0.10 (0.06-0.17)	0.10 (0.07-0.15)

^{^a}

Incidence ratio ratios for COVID-19 hospitalization not shown because interpretation was confounded by mandatory inpatient treatment of unvaccinated or partially vaccinated patients with confirmed COVID-19 infection.