Interim Estimated Effectiveness of 2025-2026 COVID-19 Vaccines in Adults Using a Test-Negative Design - Report - MDSpire

Interim Estimated Effectiveness of 2025-2026 COVID-19 Vaccines in Adults Using a Test-Negative Design

  • By

  • Ryan E. Wiegand

  • Sean Chickery

  • Duck-Hye Yang

  • Sarah W. Ball

  • Malini B. DeSilva

  • Kristin Dascomb

  • Stephanie A. Irving

  • Karthik Natarajan

  • Nicola P. Klein

  • Shaun J. Grannis

  • Toan C. Ong

  • Elizabeth A. K. Rowley

  • Adam Yates

  • Yan Zhuang

  • Sarah Wilson

  • Charlene E. McEvoy

  • Inih J. Essien

  • Omobosola O. Akinsete

  • Allison L. Naleway

  • Padma Koppolu

  • Ousseny Zerbo

  • John R. Hansen

  • Karen B. Jacobson

  • Lawrence Block

  • Brian E. Dixon

  • Thomas Duszynski

  • Colin Rogerson

  • Michelle A. Barron

  • Catia Chavez

  • Josephine Mak

  • Allison Avrich Ciesla

  • Monica Godfrey

  • Amber Kautz

  • Morgan Najdowski

  • Ruth Link-Gelles

  • Jennifer DeCuir

  • Amanda B. Payne

  • June 23, 2026

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Clinical Report: Preliminary Assessment of COVID-19 Vaccine Effectiveness 2025-2026

Background

COVID-19 continues to pose a significant public health challenge, with substantial hospitalization rates, particularly among older adults. The introduction of new vaccine formulations necessitates ongoing evaluation of their effectiveness.

Data Highlights

No specific numerical data was provided in the source material.

Key Findings

  • The study utilized a test-negative design to assess vaccine effectiveness.
  • Data were collected from 253 emergency departments and urgent care sites across 7 states.
  • Eligible participants included immunocompetent adults aged 18 years or older with COVID-19-like illness.
  • Vaccination history was obtained from immunization information systems and electronic health records.
  • COVID-19 vaccination was defined as receiving a vaccine at least 7 days prior to the encounter.

Clinical Implications

Clinicians should remain informed about the latest vaccine recommendations and effectiveness data.

Conclusion

Ongoing evaluation of COVID-19 vaccines is necessary.

Related Resources & Content

  1. FDA, COVID-19 Vaccines (2025-2026 Formula) for Use in the United States Beginning in Fall 2025
  2. JAMA Network Open, Why the Test-Negative Design Is Used for Routine Vaccine Monitoring
  3. Kaiser Family Foundation, Estimating Effectiveness of Influenza and COVID-19 Vaccines: The “Test-Negative” Design
  4. JAMA Network Open, COVID-19 Vaccine Effectiveness Among Older Adults
  5. Open Forum Infectious Diseases, Efficacy and Longevity of the BNT162b2 KP.2 Vaccine in Preventing COVID-19 Hospitalizations
  6. CDC, Respiratory Virus Activity — United States, July 1, 2024–June 30, 2025
  7. CDC, Vaccine Effectiveness | COVID-19
  8. COVID-19 Vaccines (2025-2026 Formula) for Use in the United States Beginning in Fall 2025 | FDA
  9. Respiratory Virus Activity — United States, July 1, 2024–June 30, 2025 | MMWR
  10. Vaccine Effectiveness | COVID-19 | CDC

Original Source(s)

Interim Estimated Effectiveness of 2025-2026 COVID-19 Vaccines in Adults Using a Test-Negative Design

  • by Ryan E. Wiegand, Sean Chickery, Duck-Hye Yang, Sarah W. Ball, Malini B. DeSilva, Kristin Dascomb, Stephanie A. Irving, Karthik Natarajan, Nicola P. Klein, Shaun J. Grannis, Toan C. Ong, Elizabeth A. K. Rowley, Adam Yates, Yan Zhuang, Sarah Wilson, Charlene E. McEvoy, Inih J. Essien, Omobosola O. Akinsete, Allison L. Naleway, Padma Koppolu, Ousseny Zerbo, John R. Hansen, Karen B. Jacobson, Lawrence Block, Brian E. Dixon, Thomas Duszynski, Colin Rogerson, Michelle A. Barron, Catia Chavez, Josephine Mak, Allison Avrich Ciesla, Monica Godfrey, Amber Kautz, Morgan Najdowski, Ruth Link-Gelles, Jennifer DeCuir, Amanda B. Payne

  • June 23, 2026

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