Embi, Peter J.Levy, Matthew E.Naleway, Allison L.Patel, PalakGaglani, ManjushaNatarajan, KarthikDascomb, KristinOng, Toan C.Klein, Nicola P.Liao, I-ChiaGrannis, Shaun J.Han, JungmiStenehjem, EdwardDunne, Margaret M.Lewis, NedIrving, Stephanie A.Rao, SuchitraMcEvoy, CharleneBozio, Catherine H.Murthy, KempapuraDixon, Brian E.Grisel, NancyYang, Duck-HyeGoddard, KristinKharbanda, Anupam B.Reynolds, SueRaiyani, ChandniFadel, William F.Arndorfer, JulieRowley, Elizabeth A.Fireman, BruceFerdinands, JillValvi, Nimish R.Ball, Sarah W.Zerbo, OussenyGriggs, Eric P.Mitchell, Patrick K.Porter, Rachael M.Kiduko, Salome A.Blanton, LeneeZhuang, YanSteffens, AndreaReese, Sarah E.Olson, NatalieWilliams, JeremiahDickerson, MonicaMcMorrow, MeredithSchrag, Stephanie J.Verani, Jennifer R.Fry, Alicia M.Azziz-Baumgartner, EduardoBarron, Michelle A.Thompson, Mark G.DeSilva, Malini B.2022-02-242022-02-242021-11Embi, P. J., Levy, M. E., Naleway, A. L., Patel, P., Gaglani, M., Natarajan, K., Dascomb, K., Ong, T. C., Klein, N. P., Liao, I.-C., Grannis, S. J., Han, J., Stenehjem, E., Dunne, M. M., Lewis, N., Irving, S. A., Rao, S., McEvoy, C., Bozio, C. H., … DeSilva, M. B. (2021). Effectiveness of 2-Dose Vaccination with mRNA COVID-19 Vaccines Against COVID-19–Associated Hospitalizations Among Immunocompromised Adults—Nine States, January–September 2021. MMWR. Morbidity and Mortality Weekly Report, 70(44), 1553–1559. https://doi.org/10.15585/mmwr.mm7044e30149-2195, 1545-861Xhttps://hdl.handle.net/1805/27935What is already known about this topic? Studies suggest that immunocompromised persons who receive COVID-19 vaccination might not develop high neutralizing antibody titers or be as protected against severe COVID-19 outcomes as are immunocompetent persons. What is added by this report? Effectiveness of mRNA vaccination against laboratory-confirmed COVID-19–associated hospitalization was lower (77%) among immunocompromised adults than among immunocompetent adults (90%). Vaccine effectiveness varied considerably among immunocompromised patient subgroups. What are the implications for public health practice? Immunocompromised persons benefit from COVID-19 mRNA vaccination but are less protected from severe COVID-19 outcomes than are immunocompetent persons. Immunocompromised persons receiving mRNA COVID-19 vaccines should receive 3 doses and a booster, consistent with CDC recommendations, practice nonpharmaceutical interventions, and, if infected, be monitored closely and considered early for proven therapies that can prevent severe outcomes.en-USCC0 1.0 Universal (CC0 1.0)immunocompromised personsCovid-19COVID-19 vaccinationantibody titersmRNA vaccinationArticle