. 2022 Jan 28;71(4):118–124. doi: 10.15585/mmwr.mm7104a2

TABLE 3. Effectiveness of 2-dose and 3-dose regimens of COVID-19 mRNA vaccines against COVID-19 hospitalization among adults with and without immunocompromising conditions — 21 hospitals, 18 U.S. states,*^,^† August–December 2021.

Subgroup	Vaccinated versus unvaccinated, 2 doses		Vaccinated versus unvaccinated, 3 doses		P-value for VE comparison for 2-dose versus 3-dose recipients^§
Subgroup	No. vaccinated/Total no. (%)	VE (95% CI)*	No. vaccinated/Total no. (%)	VE (95% CI)*
Patients without immunocompromising conditions
COVID-19 case-patients	212/956 (22)	82 (77–86)	10/754 (1)	97 (95–99)	<0.001
Control patients	467/788 (59)	82 (77–86)	121/442 (27)	97 (95–99)	<0.001
Patients with immunocompromising conditions
COVID-19 case-patients	196/383 (51)	69 (57–78)	36/223 (16)	88 (81–93)	<0.001
Control patients	376/513 (73)	69 (57–78)	145/282 (51)	88 (81–93)	<0.001

Abbreviation: VE = vaccine effectiveness.

* VE was estimated using logistic regression, comparing the odds of being vaccinated with the Moderna or Pfizer-BioNTech COVID-19 vaccine product versus being unvaccinated among case-patients and controls using the equation VE = 100 × (1 – adjusted odds ratio). The regression model included three categories for vaccination status: unvaccinated, vaccinated with 2 doses of an mRNA vaccine, or vaccinated with 3 doses of an mRNA vaccine. VE was calculated separately comparing 2-dose recipients to unvaccinated controls and 3-dose recipients to unvaccinated controls. Models were adjusted for date of hospital admission (biweekly intervals), U.S. Department of Health and Human Services region of hospital, age group (18–49, 50–64, or ≥65 years), sex, and race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic of any race, non-Hispanic Other, or unknown).

† Hospitals by U.S. Department of Health and Human Services region included: Region 1: Baystate Medical Center (Springfield, Massachusetts), Beth Israel Deaconess Medical Center (Boston, Massachusetts); Region 2: Montefiore Medical Center (New York City borough of the Bronx, New York); Region 3: The Johns Hopkins Hospital (Baltimore, Maryland); Region 4: Vanderbilt University Medical Center (Nashville, Tennessee), University of Miami Medical Center (Miami, Florida), Emory University Hospital (Atlanta, Georgia), Atrium Health Wake Forest Baptist Medical Center (Winston-Salem, North Carolina); Region 5: University of Michigan Hospital (Ann Arbor, Michigan), Hennepin County Medical Center (Minneapolis, Minnesota), Cleveland Clinic (Cleveland, Ohio), The Ohio State University Wexner Medical Center (Columbus, Ohio); Region 6: Baylor Scott & White Medical Center (Temple, Texas); Region 7: University of Iowa Hospitals & Clinics (Iowa City, Iowa), Barnes Jewish Hospital (St. Louis, Missouri); Region 8: UCHealth University of Colorado Hospital (Aurora, Colorado), Intermountain Medical Center (Murray, Utah); Region 9: Stanford University Medical Center (Palo Alto, California), Ronald Reagan UCLA Medical Center (Los Angeles, California); Region 10: Oregon Health & Science University Hospital (Portland, Oregon), University of Washington Medical Center (Seattle, Washington).

^§ Post-hoc pairwise comparisons of VE for 2-dose versus 3-dose vaccine recipients was evaluated using the pwcompare function in Stata software (version 16; StataCorp); a two sided p-value <0.05 indicated a significant difference in VE between groups.

TABLE 3. Effectiveness of 2-dose and 3-dose regimens of COVID-19 mRNA vaccines against COVID-19 hospitalization among adults with and without immunocompromising conditions — 21 hospitals, 18 U.S. states,*,† August–December 2021.

TABLE 3. Effectiveness of 2-dose and 3-dose regimens of COVID-19 mRNA vaccines against COVID-19 hospitalization among adults with and without immunocompromising conditions — 21 hospitals, 18 U.S. states,*^,^† August–December 2021.