Interim Estimates of 2023–24 Seasonal Influenza Vaccine Effectiveness — United States
Authors: Aaron M. Frutos, Ashley M. Price, Elizabeth Harker, Emily L. Reeves, Haris M. Ahmad, Vel Murugan, Emily T. Martin, Stacey House, Elie A. Saade, Richard K. Zimmerman, Manjusha Gaglani, Karen J. Wernli, Emmanuel B. Walter, Marian G. Michaels, Mary A. Staat, Geoffrey A. Weinberg, Rangaraj Selvarangan, Julie A. Boom, Eileen J. Klein, Natasha B. 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 W. 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, Adam S. Lauring, Julie Arndorfer, Daniel Bride, Ithan D. Peltan, Nicholas M. Mohr, David N. Hager, Matthew Prekker, Amira Mohamed, Nicholas Johnson, Jay 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 M. 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 Faryar, Robert A. Salata, Krissy Moehling Geffel, Mary Patricia Nowalk, Kempapura Murthy, Spencer Rose, Michael E. Smith, Brianna Wickersham, Brian D. Williamson, Natalie A.B. Bontrager, Olivia L. Williams, Joanna L. Kramer, Lora Nordstrom, Arnold S. Monto, Ivana A. Vaughn, Monica Dickerson, Callie McLean, Emma K. Noble, Caitlin Ray, Kelsey Sumner, Inih Essien, Linda Fletcher, Phillip Heaton, Sheryl Kane, Charlene McEvoy, Sunita Thapa, Gabriela Vazquez-Benitez, Cassandra Bezi, Richard Contreras, Gregg S. Davis, Bruno J. Lewin, Parag Mahale, Rudy Patrick, Lei Qian, Emily Rayens, Iris Anne C. Reyes, Denison S. Ryan, S. Bianca Salas, Lina S. Sy, Meiyu Yeh, Xi Zeng, Bruce Fireman, Kristin Goddard, John Hansen, Karen B. Jacobson, Julius Timbol, Ousseny Zerbo, Margaret Dunne, Yan Zhuang
Journal: MMWR Morbidity and Mortality Weekly Report (2024)

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 casecontrol 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.