Interim Effectiveness of Updated 2023–2024 (Monovalent XBB.1.5) COVID-19 Vaccines Against COVID-19–Associated Emergency Department and Urgent Care Encounters and Hospitalization Among Immunocompetent Adults Aged ≥18 Years — VISION and IVY Networks, September 2023–January 2024
Authors: Jennifer DeCuir, Amanda B. Payne, Wesley H. Self, Elizabeth A.K. Rowley, Kristin Dascomb, Malini B. DeSilva, Stephanie A. Irving, Shaun J. Grannis, Toan C. Ong, Nicola P. Klein, Zachary A. Weber, Sarah E. Reese, Sarah W. Ball, Michelle A. Barron, Allison L. Naleway, Brian E. Dixon, Inih Essien, Daniel Bride, Karthik Natarajan, Bruce Fireman, Ami B. Shah, Erica Okwuazi, Ryan Wiegand, Yuwei Zhu, Adam S. Lauring, Emily T. Martin, Manjusha Gaglani, Ithan D. Peltan, Samuel M. Brown, Adit A. Ginde, Nicholas M. Mohr, Kevin W. Gibbs, David N. Hager, Matthew Prekker, Amira Mohamed, Vasisht Srinivasan, Jay S. Steingrub, Akram Khan, Laurence W. Busse, Abhijit Duggal, Jennifer G. Wilson, Steven Y. Chang, Christopher Mallow, Jennie H. Kwon, Matthew C. Exline, Cristie Columbus, Ivana A. Vaughn, Basmah Safdar, Jarrod M. Mosier, Estelle S. Harris, Jonathan D. Casey, James D. Chappell, Carlos G. Grijalva, Sydney A. Swan, Cassandra Johnson, Nathaniel M. Lewis, Sascha Ellington, Katherine Adams, Mark W. Tenforde, Clinton R. Paden, Fatimah S. Dawood, Katherine E. Fleming-Dutra, Diya Surie, Ruth Link-Gelles, Shekhar Ghamande, Robert Gottlieb, Tresa McNeal, Catherine Raver, William Bender, Linda Fletcher, Phillip Heaton, Sheryl Kane, Charlene McEvoy, Sunita Thapa, Gabriela Vazquez-Benitez, Anne Frosch, Lois E Lamerato, Mayur Ramesh, Julie Arnofer, Harith Ali, Johns Hopkins, Bradley Crane, Padma Dandamudi, Kristin Goddard, John Hansen, Julius Timbol, Ousseny Zerbo, Katie Allen, Thomas Duszynski, William Fadel, Colin Rogerson, Nida Qadir, Catia Chavez, Bryant Doyle, David Mayer, Suchitra Rao, Carolina Rivas, Nicholas J. Johnson, Adrienne Baughman, Cara T. Lwin, Jillian P. Rhoads, Kelsey N. Womack, Margaret Dunne, Allison Ciesla, Josephine Mak, Morgan Najdowski, Caitlin Ray
Journal: MMWR Morbidity and Mortality Weekly Report (2024)

In September 2023, CDC's Advisory Committee on Immunization Practices recommended updated 2023-2024 (monovalent XBB.1.5)COVID-19 vaccination for all persons aged ≥6 months to prevent COVID-19, including severe disease.However, few estimates of updated vaccine effectiveness (VE) against medically attended illness are available.This analysis evaluated VE of an updated COVID-19 vaccine dose against COVID-19-associated emergency department (ED) or urgent care (UC) encounters and hospitalization among immunocompetent adults aged ≥18 years during September 2023-January 2024 using a test-negative, case-control design with data from two CDC VE networks.VE against COVID-19-associated ED/ UC encounters was 51% (95% CI = 47%-54%) during the first 7-59 days after an updated dose and 39% (95% CI = 33%-45%) during the 60-119 days after an updated dose.VE estimates against COVID-19-associated hospitalization from two CDC VE networks were 52% (95% CI = 47%-57%) and 43% (95% CI = 27%-56%), with a median interval from updated dose of 42 and 47 days, respectively.Updated COVID-19 vaccine provided increased protection against COVID-19associated ED/UC encounters and hospitalization among immunocompetent adults.These results support CDC recommendations for updated 2023-2024 COVID-19 vaccination.All persons aged ≥6 months should receive updated 2023-2024 COVID-19 vaccine.