Interim Estimates of 2023–24 Seasonal Influenza Vaccine Effectiveness — United States
Aaron M. Frutos, Ashley M. Price, Elizabeth Harker, Emily Reeves, Haris M. Ahmad, Vel Murugan, Emily T. Martin, Stacey L. House, Elie Saade, Richard K. Zimmerman, Manjusha Gaglani, Karen J. Wernli, Emmanuel B. Walter, Marian G. Michaels, Mary Allen Staat, Geoffrey A. Weinberg, Rangaraj Selvarangan, Julie A. Boom, Eileen J. Klein, Natasha Halasa, Adit A. Ginde, Kevin W. Gibbs, Yuwei Zhu, Wesley H. Self, Sara Y. Tartof, Nicola P. Klein, Kristin Dascomb, Malini B. DeSilva, Zachary A. Weber, Duck‐Hye Yang, Sarah Ball, Diya Surie, Jennifer DeCuir, Fatimah S. Dawood, Heidi L. Moline, Ariana P. Toepfer, Benjamin R Clopper, Ruth Link‐Gelles, Amanda B. Payne, Jessie R. Chung, Brendan Flannery, Nathaniel M. Lewis, Samantha M. Olson, Katherine Adams, Mark W. Tenforde, Shikha Garg, Lisa A. Grohskopf, Carrie Reed, Sascha Ellington, CDC Influenza Vaccine Effectiveness Collaborators, CDC Influenza Vaccine Effectiveness Collaborators, Adam S. Lauring, Julie Arndorfer, Daniel Bride, Ithan D. Peltan, Nicholas M. Mohr, David N. Hager, Matthew E. Prekker, Amira Mohamed, Nicholas J. Johnson, Jay S. Steingrub, Akram Khan, Laurence W. Busse, Abhijit Duggal, Jennifer G. Wilson, Nida Qadir, Christopher Mallow, Jennie H. Kwon, Matthew C. Exline, Nathan I. Shapiro, Cristie Columbus, Ivana A. Vaughan, Jarrod Mosier, Basmah Safdar, Estelle S. Harris, James D. Chappell, Laura S Stewart, Sydney A. Swan, Pedro A. Piedra, Leila C. Sahni, Janet A. Englund, Danielle M. Zerr, Robert W. Hickey, John V. Williams, Chelsea Rohlfs, Elizabeth P. Schlaudecker, Dinah Dosdos, Mary E. Moffatt, Jennifer E. Schuster, Kirsten Weltmer, Peter G. Szilagyi, Tara Curley, Jamie Mills, Kiran A. Faryar, Robert A. Salata, Krissy Moehling Geffel, Mary Patricia Nowalk, Kempapura Murthy, Spencer Rose, Michael Smith
Abstract
In the United States, annual influenza vaccination is recommended for all persons aged ≥6 months. Using data from four vaccine effectiveness (VE) networks during the 2023-24 influenza season, interim influenza VE was estimated among patients aged ≥6 months with acute respiratory illness-associated medical encounters using a test-negative case-control study design. Among children and adolescents aged 6 months-17 years, VE against influenza-associated outpatient visits ranged from 59% to 67% and against influenza-associated hospitalization ranged from 52% to 61%. Among adults aged ≥18 years, VE against influenza-associated outpatient visits ranged from 33% to 49% and against hospitalization from 41% to 44%. VE against influenza A ranged from 46% to 59% for children and adolescents and from 27% to 46% for adults across settings. VE against influenza B ranged from 64% to 89% for pediatric patients in outpatient settings and from 60% to 78% for all adults across settings. These findings demonstrate that the 2023-24 seasonal influenza vaccine is effective at reducing the risk for medically attended influenza virus infection. CDC recommends that all persons aged ≥6 months who have not yet been vaccinated this season get vaccinated while influenza circulates locally.