Influenza Humans Commons^™

Interim Estimates Of 2025-26 Seasonal Influenza Vaccine Effectiveness - United States, September 2025-February 2026., Patrick Maloney, Emily L. Reeves, Kristina Wielgosz, Ashley M. Price, Karthik Natarajan, Malini B. Desilva, Kristin Dascomb, Nicola P. Klein, Sara Y. Tartof, Stephanie A. Irving, Shaun J. Grannis, Toan C. Ong, Zachary A. Weber, Jennifer E. Schuster, Danielle M. Zerr, Marian G. Michaels, Julie A. Boom, Natasha B. Halasa, Mary A. Staat, Geoffrey A. Weinberg, Stacey L. House, Elie A. Saade, Krissy Moehling Geffel, Manjusha Gaglani, Karen J. Wernli, Vel Murugan, Emily T. Martin, Natalie A B Bontrager, Marie K. Kirby, Amanda B. Payne, Fatimah S. Dawood, Ayzsa Tannis, Heidi L. Moline, Sifang Kathy Zhao, Katherine Adams, Jennifer Decuir, Samantha M. Olson, Jessie R. Chung, Nathaniel Lewis, Brendan Flannery, Carrie Reed, Shikha Garg, Sascha Ellington, Cdc Influenza Vaccine Effectiveness Collaborators

Manuscripts, Articles, Book Chapters and Other Papers

In the United States, annual influenza vaccination has been recommended for all persons aged ≥6 months, including during the 2025-26 season. Interim influenza vaccine effectiveness (VE) estimates were calculated for patients with acute respiratory illness-associated outpatient visits and hospitalizations from three U.S. respiratory virus VE networks during the 2025-26 influenza season, using a test-negative case-control design. Among children and adolescents aged < 18 years, VE was 38%-41% against influenza outpatient visits and 41% against influenza-associated hospitalization. Among adults aged ≥18 years, VE was 22%-34% against influenza outpatient visits and 30% against influenza-associated hospitalization. Among children and adolescents, VE against influenza A ranged from 37% (against outpatient visits) to 42% (against hospitalization) across settings; among adults, VE against influenza A ranged from 30% (against hospitalization) to 34% (against outpatient visits) across settings. Among children and adolescents, VE against influenza A(H3N2)-associated outpatient visits was 35% and against influenza A(H3N2)-associated hospitalization was 38%. VE against influenza B outpatient visits ranged from 45%-71% among children and adolescents and was 63% among adults. Other estimates of VE were not statistically significant or were not reportable. Although interim influenza VE is lower during the 2025-26 influenza season than it was during recent influenza seasons, these findings demonstrate that influenza vaccination still provides protection against influenza. CDC recommends influenza vaccination; U.S. influenza vaccines remain available for persons aged ≥6 months.

Changes In Antiviral Prescribing For Children With Influenza In Us Emergency Departments., Tess Stopczynski, Olla Hamdan, Justin Z. Amarin, James W. Antoon, Laura S. Stewart, Haya Hayek, James Chappell, Andrew J. Spieker, Eileen J. Klein, Janet A. Englund, Geoffrey A. Weinberg, Peter G. Szilagyi, John V. Williams, Marian G. Michaels, Julie A. Boom, Leila C. Sahni, Mary Allen Staat, Elizabeth P. Schlaudecker, Jennifer E. Schuster, Rangaraj Selvarangan, Ayzsa Tannis, Heidi L. Moline, Samantha M. Olson, Natasha B. Halasa

Manuscripts, Articles, Book Chapters and Other Papers

IMPORTANCE: Despite national recommendations, antiviral prescribing in emergency departments (EDs) for children at higher risk of severe influenza, such as those younger than 5 years and those with specific underlying conditions, remains low.

OBJECTIVE: To assess whether there were changes in antiviral prescribing for children at higher risk of severe influenza in academic pediatric EDs before the COVID-19 pandemic (2016-2020) vs the late pandemic period (2021-2023).

DESIGN, SETTING, AND PARTICIPANTS: This multicenter, cross-sectional study included influenza-positive children younger than 18 years presenting to the ED at 1 of 7 US pediatric academic hospitals participating in the Centers for Disease Control …

Clinical Testing For Covid-19, Influenza, And Rsv In Hospitalized Youths, 2016-2024., Ariana P. Toepfer, Rachel E. Rutkowski, Leila C. Sahni, Geoffrey A. Weinberg, Marian G. Michaels, Rangaraj Selvarangan, Mary Allen Staat, Natasha Halasa, Janet A. Englund, Julie A. Boom, Peter G. Szilagyi, Jennifer E. Schuster, Elizabeth P P. Schlaudecker, Laura S. Stewart, Eileen J. Klein, Samantha M. Olson, Sascha Ellington, Meredith L. Mcmorrow, Heidi L. Moline, Fatimah S. Dawood, New Vaccine Surveillance Network Collaborators

Manuscripts, Articles, Book Chapters and Other Papers

IMPORTANCE: Studies of COVID-19, influenza, and respiratory syncytial virus (RSV) disease clinical epidemiology, disease burden, and vaccine effectiveness often rely on clinical testing to identify cases, particularly with increasing use of electronic health record data. However, few data are available describing clinical testing practices to inform interpretation of these studies.

OBJECTIVE: To characterize clinical testing frequency for SARS-CoV-2, influenza, and RSV among children and adolescents hospitalized with acute respiratory illness during the 2016 to 2024 respiratory illness seasons by age, intensive care unit admission, and time period (2016-2020 and each season in 2020-2024); estimate the case fraction missed by clinical …

Interim Estimates Of 2024-2025 Seasonal Influenza Vaccine Effectiveness - Four Vaccine Effectiveness Networks, United States, October 2024-February 2025., Aaron M. Frutos, Seana Cleary, Emily L. Reeves, Haris M. Ahmad, Ashley M. Price, Wesley H. Self, Yuwei Zhu, Basmah Safdar, Ithan D. Peltan, Kevin W. Gibbs, Matthew C. Exline, Adam S. Lauring, Sarah W. Ball, Malini Desilva, Sara Y. Tartof, Kristin Dascomb, Stephanie A. Irving, Nicola P. Klein, Brian E. Dixon, Toan C. Ong, Ivana A. Vaughn, Stacey L. House, Kiran A. Faryar, Mary Patricia Nowalk, Manjusha Gaglani, Karen J. Wernli, Vel Murugan, Olivia L. Williams, Rangaraj Selvarangan, Geoffrey A. Weinberg, Mary A. Staat, Natasha B. Halasa, Leila C. Sahni, Marian G. Michaels, Janet A. Englund, Marie K. Kirby, Diya Surie, Fatimah S. Dawood, Benjamin R. Clopper, Heidi L Moline, Ruth Link-Gelles, Amanda B. Payne, Elizabeth Harker, Kristina Wielgosz, Zachary A. Weber, Duck-Hye Yang, Nathaniel M. Lewis, Jennifer Decuir, Samantha M. Olson, Jessie R. Chung, Brendan Flannery, Lisa A. Grohskopf, Carrie Reed, Shikha Garg, Sascha Ellington, Cdc Influenza Vaccine Effectiveness Collaborators

Manuscripts, Articles, Book Chapters and Other Papers

Annual influenza vaccination is recommended for all persons aged ≥6 months in the United States. Interim influenza vaccine effectiveness (VE) was calculated among patients with acute respiratory illness-associated outpatient visits and hospitalizations from four VE networks during the 2024-25 influenza season (October 2024-February 2025). Among children and adolescents agedyears, VE against any influenza was 32%, 59%, and 60% in the outpatient setting in three networks, and against influenza-associated hospitalization was 63% and 78% in two networks. Among adults aged ≥18 years, VE in the outpatient setting was 36% and 54% in two networks and was 41% and 55% against hospitalization …

Covid-19 Vaccine Hesitancy Among Black Women In The Us, Brittany C Slatton, Farrah G Cambrice, Serwaa S Omowale

Faculty, Staff and Student Publications

IMPORTANCE: COVID-19 vaccine hesitancy among Black women is a critical public health concern, potentially exacerbating existing health disparities and impacting community-wide vaccination efforts.

OBJECTIVE: To explore the factors associated with COVID-19 vaccine hesitancy among Black women in the US and identify the specific concerns and experiences shaping hesitant attitudes toward vaccination.

DESIGN, SETTING, AND PARTICIPANTS: Qualitative study using in-depth, semistructured interviews conducted virtually between June and November 2021. Thematic analysis was used to identify key themes from the interview data. Participants were recruited through social media platforms and word-of-mouth referrals from various regions of the US. Interviews were conducted remotely …

Protective Effects Of Psychiatric Medications Against Covid-19 Mortality Before Vaccines, Rodrigo Machado-Vieira, Trudy M Krause, Gregory Jones, Antonio L Teixeira, Lokesh R Shahani, Scott D Lane, Jair C Soares, Chau N Truong

Faculty, Staff and Student Publications

The coronavirus disease pandemic caused by the coronavirus SARS-CoV-2, which emerged in the United States in late 2019 to early 2020 and quickly escalated into a national public health crisis. Research has identified psychiatric conditions as possible risk factors associated with COVID-19 infection and symptom severity. This study aims to determine whether specific classes of psychiatric medications could reduce the likelihood of infection and alleviate the severity of the disease. The objective of this study is to investigate the relationship between neuropsychiatric medication usage and COVID-19 outcomes before the widespread utilization of COVID-19 vaccines. This cross-sectional study used Optum's de-identified …

Estimated Vaccine Effectiveness For Pediatric Patients With Severe Influenza, 2015-2020., Kelsey M. Sumner, Leila C. Sahni, Julie A. Boom, Natasha B. Halasa, Laura S. Stewart, Janet A. Englund, Eileen J. Klein, Mary A. Staat, Elizabeth P. Schlaudecker, Rangaraj Selvarangan, Christopher J. Harrison, Geoffrey A. Weinberg, Peter G. Szilagyi, Monica N. Singer, Parvin H. Azimi, Benjamin R. Clopper, Heidi L. Moline, Emma K. Noble, John V. Williams, Marian G. Michaels, Samantha M. Olson, New Vaccine Surveillance Network Collaborators

Manuscripts, Articles, Book Chapters and Other Papers

IMPORTANCE: Increasing the understanding of vaccine effectiveness (VE) against levels of severe influenza in children could help increase uptake of influenza vaccination and strengthen vaccine policies globally.

OBJECTIVE: To investigate VE in children by severity of influenza illness.

DESIGN, SETTING, AND PARTICIPANTS: This case-control study with a test-negative design used data from 8 participating medical centers located in geographically different US states in the New Vaccine Surveillance Network from November 6, 2015, through April 8, 2020. Participants included children 6 months through 17 years of age who were hospitalized or presented to an emergency department (ED) with acute respiratory illness. …

Underutilization Of Influenza Antiviral Treatment Among Children And Adolescents At Higher Risk For Influenza-Associated Complications - United States, 2023-2024., Aaron M. Frutos, Haris M. Ahmad, Dawud Ujamaa, Alissa C. O'Halloran, Janet A. Englund, Eileen J. Klein, Danielle M. Zerr, Melanie Crossland, Holly Staten, Julie A. Boom, Leila C. Sahni, Natasha B. Halasa, Laura S. Stewart, Olla Hamdan, Tess Stopczynski, William Schaffner, H Keipp Talbot, Marian G. Michaels, John V. Williams, Melissa Sutton, M Andraya Hendrick, Mary A. Staat, Elizabeth P. Schlaudecker, Brenda L. Tesini, Christina B. Felsen, Geoffrey A. Weinberg, Peter G. Szilagyi, Bridget J. Anderson, Jemma V. Rowlands, Murtada Khalifa, Marc Martinez, Rangaraj Selvarangan, Jennifer E. Schuster, Ruth Lynfield, Melissa Mcmahon, Sue Kim, Val Tellez Nunez, Patricia A. Ryan, Maya L. Monroe, Yun F. Wang, Kyle P. Openo, James Meek, Kimberly Yousey-Hindes, Nisha B. Alden, Isaac Armistead, Suchitra Rao, Shua J. Chai, Pam Daily Kirley, Ariana P. Toepfer, Fatimah S. Dawood, Heidi L. Moline, Timothy M. Uyeki, Sascha Ellington, Shikha Garg, Catherine H. Bozio, Samantha M. Olson

Manuscripts, Articles, Book Chapters and Other Papers

Annually, tens of thousands of U.S. children and adolescents are hospitalized with seasonal influenza virus infection. Both influenza vaccination and early initiation of antiviral treatment can reduce complications of influenza. Using data from two U.S. influenza surveillance networks for children and adolescents agedattended, laboratory-confirmed influenza for whom antiviral treatment is recommended, the percentage who received treatment was calculated. Trends in antiviral treatment of children and adolescents hospitalized with influenza from the 2017-18 to the 2023-2024 influenza seasons were also examined. Since 2017-18, when 70%-86% of hospitalized children and adolescents with influenza received antiviral treatment, the proportion receiving treatment notably declined. …

A Phase 2 Clinical Trial To Evaluate The Safety, Reactogenicity, And Immunogenicity Of Different Prime-Boost Vaccination Schedules Of 2013 And 2017 A(H7n9) Inactivated Influenza Virus Vaccines Administered With And Without As03 Adjuvant In Healthy Us Adults, Christina A Rostad, Robert L Atmar, Emmanuel B Walter, Sharon Frey, Jeffery L Meier, Amy C Sherman, Lilin Lai, Rachel Tsong, Carol M Kao, Vanessa Raabe, Hana M El Sahly, Wendy A Keitel, Jennifer A Whitaker, Michael J Smith, Kenneth E Schmader, Geeta K Swamy, Getahun Abate, Patricia Winokur, Wendy Buchanan, Kaitlyn Cross, Ashley Wegel, Yongxian Xu, Inci Yildirim, Satoshi Kamidani, Nadine Rouphael, Paul C Roberts, Mark J Mulligan, Evan J Anderson

Center for Medical Ethics and Health Policy Staff Publications

Introduction: A surge of human influenza A(H7N9) cases began in 2016 in China from an antigenically distinct lineage. Data are needed about the safety and immunogenicity of 2013 and 2017 A(H7N9) inactivated influenza vaccines (IIVs) and the effects of AS03 adjuvant, prime-boost interval, and priming effects of 2013 and 2017 A(H7N9) IIVs.

Methods: Healthy adults (n = 180), ages 19-50 years, were enrolled into this partially blinded, randomized, multicenter phase 2 clinical trial. Participants were randomly assigned to 1 of 6 vaccination groups evaluating homologous versus heterologous prime-boost strategies with 2 different boost intervals (21 vs 120 days) and 2 …

Accuracy Of Influenza Icd-10 Diagnosis Codes In Identifying Influenza Illness In Children., James W. Antoon, Tess Stopczynski, Justin Z. Amarin, Laura S. Stewart, Julie A. Boom, Leila C. Sahni, Marian G. Michaels, John V. Williams, Janet A. Englund, Eileen J. Klein, Mary A. Staat, Elizabeth P. Schlaudecker, Rangaraj Selvarangan, Jennifer E. Schuster, Geoffrey A. Weinberg, Peter G. Szilagyi, Ariana Perez, Heidi L. Moline, Andrew J. Spieker, Carlos G. Grijalva, Samantha M. Olson, Natasha B. Halasa

Manuscripts, Articles, Book Chapters and Other Papers

IMPORTANCE: Studies of influenza in children commonly rely on coded diagnoses, yet the ability of International Classification of Diseases, Ninth Revision codes to identify influenza in the emergency department (ED) and hospital is highly variable. The accuracy of newer International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes to identify influenza in children is unknown.

OBJECTIVE: To determine the accuracy of ICD-10 influenza discharge diagnosis codes in the pediatric ED and inpatient settings.

DESIGN, SETTING, AND PARTICIPANTS: Children younger than 18 years presenting to the ED or inpatient settings with fever and/or respiratory symptoms at 7 …

Exploring The Relationship Between Vaccine Hesitancy And Mothers’ Perspectives On Covid-19 Vaccines For Children Ages 5–11 Years During The Omicron Predominant Period 2021–2022: A Qualitative Study, Tiffany A Suragh, David Adzrago, Marlyn A Allicock, Paul G Yeh, Paula Cuccaro

Faculty, Staff and Student Publications

Background: The United States Food and Drug Administration authorized COVID-19 vaccines for children ages 5-11 years in October 2021 during the Omicron predominant period. Parental vaccine hesitancy was prevalent during this time, resulting in low childhood COVID-19 vaccine uptake. Most studies exploring factors influencing parental vaccine hesitancy have focused on racial and ethnic minorities and lower socioeconomic populations; however, there is little knowledge of the drive drivers of vaccine hesitancy among White parents with higher education and socioeconomic statuses.

Methods: We conducted semi-structured interviews with a sample of 15 White mothers of children ages 5-11 years in Atlanta, GA, between …

The Influence Of Political Ideology On Awareness Of Hpv And Hpv Vaccine Among Adults In The United States, Onyema Greg Chido-Amajuoyi, Henry Onyeaka, Hermioni Amonoo, Sanjay Shete

Faculty, Staff and Student Publications

This study aimed to investigate the association between political ideology and awareness of HPV and HPV vaccine among US adults. Study data were derived from Health Information National Trends Survey 5 Cycle 4, a 2020 cross-sectional survey of US adults. Multivariable logistic regressions were conducted to examine the association between political ideology with HPV and HPV vaccine awareness. A total of 3418 adults participated in the study, with the majority being non-Hispanic White individuals and women. The results showed that 66.1% and 62.3% of the participants were aware of HPV and HPV vaccine, respectively. A total of 36.9%, 29.7% and …

Individual, Systemic And State Factors Associated With Provider Recommendation Of Hpv Vaccination: Findings From Nis-Teen, 2020, Ikponmwosa Osaghae, Monalisa Chandra, Rajesh Talluri, Sanjay Shete

Faculty, Staff and Student Publications

The most important determinant of HPV vaccination uptake is healthcare provider recommendation, yet not all eligible patients receive HPV vaccination recommendations. We used data from the 2020 National Immunization Survey-Teen to determine individual, systemic, and state factors associated with provider recommendation of HPV vaccination. A total of 18,534 teens were included, with 81.4% receiving provider recommendations for HPV vaccination. HPV vaccination recommendation was higher among females compared to males (AOR: 1.57; 95% CI: 1.27-1.93), teens who received a well-child exam at 11 or 12 years compared to those who did not (AOR: 2.10; 95% CI: 1.61-2.74), and teens whose mothers …

Vaccine Hesitancy And Betrayal Aversion, Abdelaziz Alsharawy, Esha Dwibedi, Jason Aimone, Sheryl Ball

Faculty, Staff and Student Publications

The determinants of vaccine hesitancy remain complex and context specific. Betrayal aversion occurs when an individual is hesitant to risk being betrayed in an environment involving trust. In this pre-registered vignette experiment, we show that betrayal aversion is not captured by current vaccine hesitancy measures despite representing a significant source of unwillingness to be vaccinated. Our survey instrument was administered to 888 United States residents via Amazon Mechanical Turk in March 2021. We find that over a third of participants have betrayal averse preferences, resulting in an 8-26% decline in vaccine acceptance, depending on the betrayal source. Interestingly, attributing betrayal …

Clinical Influenza Testing Practices In Hospitalized Children At United States Medical Centers, 2015-2018., Mark W. Tenforde, Angela P. Campbell, Marian G. Michaels, Christopher J. Harrison, Eileen J. Klein, Janet A. Englund, Rangaraj Selvarangan, Natasha B. Halasa, Laura S. Stewart, Geoffrey A. Weinberg, John V. Williams, Peter G. Szilagyi, Mary A. Staat, Julie A. Boom, Leila C. Sahni, Monica N. Singer, Parvin H. Azimi, Richard K. Zimmerman, Monica M. Mcneal, H Keipp Talbot, Arnold S. Monto, Emily T. Martin, Manjusha Gaglani, Fernanda P. Silveira, Donald B. Middleton, Jill M. Ferdinands, Melissa A. Rolfes

Manuscripts, Articles, Book Chapters and Other Papers

At nine US hospitals that enrolled children hospitalized with acute respiratory illness (ARI) during 2015-2016 through 2017-2018 influenza seasons, 50% of children with ARI received clinician-initiated testing for influenza and 35% of cases went undiagnosed due to lack of clinician-initiated testing. Marked heterogeneity in testing practice was observed across sites.

Non-Mumps Viral Parotitis During The 2014-2015 Influenza Season In The United States., Lina I. Elbadawi, Pamela Talley, Melissa A. Rolfes, Alexander J. Millman, Erik Reisdorf, Natalie A. Kramer, John R. Barnes, Lenee Blanton, Jaime Christensen, Stefanie Cole, Tonya Danz, John J. Dreisig, Rebecca Garten, Thomas Haupt, Beth M. Isaac, Mary Anne Jackson, Anna Kocharian, Daniel Leifer, Karen Martin, Lisa Mchugh, Rebecca J. Mcnall, Jennifer Palm, Kay W. Radford, Sara Robinson, Jennifer B. Rosen, Senthilkumar K. Sakthivel, Peter Shult, Anna K. Strain, George Turabelidze, Lori A. Webber, Meghan Pearce Weinberg, David E. Wentworth, Brett L. Whitaker, Lyn Finelli, Michael A. Jhung, Ruth Lynfield, Jeffrey P. Davis

Manuscripts, Articles, Book Chapters and Other Papers

Background: During the 2014-2015 US influenza season, 320 cases of non-mumps parotitis (NMP) among residents of 21 states were reported to the Centers for Disease Control and Prevention (CDC). We conducted an epidemiologic and laboratory investigation to determine viral etiologies and clinical features of NMP during this unusually large occurrence.

Methods: NMP was defined as acute parotitis or other salivary gland swelling of >2 days duration in a person with a mumps- negative laboratory result. Using a standardized questionnaire, we collected demographic and clinical information. Buccal samples were tested at the CDC for selected viruses, including mumps, influenza, human parainfluenza …

Influenza-Associated Parotitis During The 2014-2015 Influenza Season In The United States., Melissa A. Rolfes, Alexander J. Millman, Pamela Talley, Lina I. Elbadawi, Natalie A. Kramer, Joh R. Barnes, Lenee Blanton, Jeffrey P. Davis, Stefanie Cole, John J. Dreisig, Rebecca Garten, Thomas Haupt, Mary Anne Jackson, Anna Kocharian, Daniel Leifer, Ruth Lynfield, Karen Martin, Lisa Mchugh, Sara Robinson, George Turabelidze, Lori A. Webber, Meghan Pearce Weinberg, David E. Wentworth, Lyn Finelli, Michael A. Jhung

Manuscripts, Articles, Book Chapters and Other Papers

Background: During the 2014-2015 influenza season in the United States, 256 cases of influenza-associated parotitis were reported from 27 states. We conducted a case-control study and laboratory investigation to further describe this rare clinical manifestation of influenza.

Methods: During February 2015-April 2015, we interviewed 50 cases (with parotitis) and 124 ill controls (without parotitis) with laboratory-confirmed influenza; participants resided in 11 states and were matched by age, state, hospital admission status, and specimen collection date. Influenza viruses were characterized using real-time polymerase chain reaction and next-generation sequencing. We compared cases and controls using conditional logistic regression. Specimens from additional reported …

Haemophilus Influenzae Type B Invasive Disease In Amish Children, Missouri, Usa, 2014, Angela L. Myers, Mary Anne Jackson, Lixin Zhang, Douglas S. Swanson, Janet R. Gilsdorf

Manuscripts, Articles, Book Chapters and Other Papers

© 2017, Centers for Disease Control and Prevention (CDC). All rights reserved. During 5 months in 2014, three Amish children in Missouri, USA, were diagnosed with invasive Haemophilus influenzae type b infection. Two were rural neighbors infected with a genetically similar rare strain, sequence type 45. One child had recently traveled, raising the possibility of maintenance of this strain among unvaccinated carriers in Amish communities.