Influenza Vaccination and Symptom Burden in Ambulatory Patients With Confirmed Influenza: Evidence From Case-ascertained Household Transmission Studies
Year: 2026
Type: article
Study design: Observational Study
Abstract: BACKGROUND: The extent to which influenza vaccination may temper disease remains uncertain. We compared symptoms between influenza vaccinated and unvaccinated ambulatory persons with influenza. METHODS: We conducted household transmission studies across multiple US sites during consecutive influenza seasons from 2017-2018 through 2022-2023 (excluding 2020-2021 season with minimal influenza activity). We collected daily symptom diaries and respiratory specimens. Three scores were calculated, varying weights on specific symptoms: 1) influenza-like illness (ILI); 2) lower respiratory; and 3) all symptoms. For each score, we examined the daily mean score between those vaccinated and unvaccinated against influenza using weighted multivariable linear mixed effects and frailty models. RESULTS: Study included 869 children (41% vaccinated, 47% female, 58% white, non-Hispanic) and 653 adults (42% vaccinated, 65% female, 72% white, non-Hispanic) with laboratory-confirmed influenza. In multivariable analyses, the mean difference in the daily ILI score was -0.16 (95% CI: -0.32, -0.01) between vaccinated and unvaccinated children and -0.18 (95% CI: -0.34, -0.01) for the lower respiratory score. There was no significant difference among adults. Influenza vaccination was not associated with time to symptom alleviation among children. However, ILI symptom alleviation occurred earlier among vaccinated (HR: 1.30, 95% CI: 1.04, 1.62) adults. CONCLUSION: Ambulatory children with influenza who were vaccinated experienced less ILI symptom burden compared to those who were not vaccinated against influenza, but vaccination was not associated with symptom duration. Conversely, among ambulatory adults with influenza, vaccination and symptom burden were not associated, but vaccination was associated with faster alleviation of ILI symptoms.
Source: Clinical Infectious Diseases
DOI: 10.1093/cid/ciag486
Authors: Amanda C Howa, Yuwei Zhu, Trey McGonigle, Huong Q Nguyen, Melissa S Stockwell, Yvonne Maldonado, Karen Lutrick, Natalie M Bowman, Suchitra Rao, Jonathan Schmitz, Son H McLaren, Ellen Sano, Clea Sarnquist, Sara Goodman, Joshua G Petrie, Kathy Pryor, Ayla Bullock, Amy Yang, Jessica E Biddle, Sheroi Johnson, Sarah E Smith-Jeffcoat, Edwin Asturias, Kate Ellingson, Celibell Y Vargas, Natasha Halasa, James Chappell, Edward A Belongia, Melissa A Rolfes, Alexandra Mellis, H Keipp Talbot, Carlos G Grijalva, Respiratory Virus Transmission Network—Sentinel Study Group, Erica Anderson, Bryan Blette, Jorge Celedonio, Allison Chan, Daniel Chandler, James Chappell, Nicola Chiwandire, Sydney Cornelison, Brittany Creasman, Ryan Dalforno, Shawn Garbett, Sarah Gleason, Carlos Grijalva, Natasha Halasa, Amanda Howa, Xiang Huang, Tiffany Israel, Andrea Ito, Emily Jookar, Judy King, Dandan Liu, Stephanie Longmire, Cara Lwin, Samuel Massion, Trey McGonigle, Rendie McHenry, John Meghreblian, Lauren Milner, Maria Padilla-Azain, Alexis Perry, John Resser, Brianna Schibley-Laird, Jonathan Schmitz, Samuel Massion, Lan Shi, In Hae Shi, Andrea Stafford Hintz, H Keipp Talbot, Dayna Wyatt, Paige Yates, Panpan Zhang, Yuwei Zhu
Institutions: Vanderbilt University Medical Center, Marshfield Clinic Research Foundation, Marshfield Clinic Research Institute, Columbia University Irving Medical Center, Stanford Medicine, Stanford University, University of Arizona, University of North Carolina at Chapel Hill, Children's Hospital Colorado, University of Colorado Denver, Centers for Disease Control and Prevention
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,763
OpenAlex ID: W7202390283