Table 9. 21-day hospitalization, 21-day ICU admission, and 28-day mortality rates among breakthrough cases from the matched mRNA-1273 and BNT162b2 cohorts.

The columns are: (1) Outcome: the clinical metric of COVID-19 severity assessed in the given row; (1) mRNA-1273 Breakthrough Cohort: cumulative incidence of the given outcome among mRNA-1273 breakthrough cases; (2) Prevalence in BNT162b2 Breakthrough Cohort: cumulative incidence of the given outcome among mRNA-1273 breakthrough cases; (3) Risk Ratio (95% CI): for the given outcome, cumulative incidence in the mRNA-1273-vaccinated cohort divided by cumulative incidence in the BNT162b2-vaccinated cohort, along with the 95% confidence interval; (4) Risk Ratio (95% CI): for the given outcome, cumulative incidence in the mRNA-1273-vaccinated cohort divided by cumulative incidence in the BNT162b2-vaccinated cohort, along with the 95% confidence interval. (5) Fisher Exact P-Value: for the given outcome, the p-value from a Fisher exact test performed on a two-by-two table of vaccine group (mRNA-1273 versus BNT162b2) by outcome status (Yes versus No).

Outcome	mRNA-1273 Breakthrough Cohort	BNT162b2 Breakthrough Cohort	Risk Ratio (95% CI)	Fisher Exact P-Value
21-Day Hospitalization	11/48 (22.9%)	27/103 (26.2%)	0.87 (0.49, 1.6)	0.84
21-Day ICU Admission	2/48 (4.2%)	5/103 (4.9%)	0.86 (0.22, 4.1)	1
28-Day Mortality	1/48 (2.1%)	0/87 (0.0%)	inf (0.22, inf)	0.36