178 - Vaccine Effectiveness Against Influenza-associated Hospitalizations and Emergency Department (ED) Visits Among Children in the United States in the 2019–2020 Season

Background: The 2019-20 influenza season was predominated by early onset B/Victoria viruses followed by A(H1N1)pdm09 virus circulation. Over 95% of circulating B/Victoria viruses were subclade V1A.3, different from the Northern Hemisphere vaccine strain. Annual estimates of influenza vaccine effectiveness (VE) are important because of frequent changes in circulating and vaccine viruses.

Methods: We assessed VE among children 6 months–17 years old with acute respiratory illness and <10 days of symptoms enrolled during the 2019-20 influenza season at 7 pediatric hospitals (ED patients < 5 years at 3 sites) in the New Vaccine Surveillance Network. Combined mid-turbinate/throat swabs were tested for influenza virus using molecular assays. We estimated age-stratified VE from a test-negative design using logistic regression to compare odds of vaccination among children testing positive versus negative for influenza, adjusting for age in years, enrollment month, and site. For these preliminary analyses, vaccination status was by parental report. 

Results: Among 2022 inpatients, 324 (16%) were influenza positive: 38% with influenza B/Victoria alone and 44% with influenza A(H1N1)pdm09 alone (Table). Among 2066 ED children, 653 (32%) were influenza positive: 45% with influenza B/Victoria alone and 43% with influenza A(H1N1)pdm09 alone. VE was 62% (95% confidence interval [CI], 51%–70%) against any influenza-related hospitalizations, 68% (95% CI, 55%–78%) for A(H1N1)pdm09 and 55% (95% CI, 35%–69%) for B/Victoria. VE by age group for any influenza-related hospitalizations was 57% (95% CI, 40%–69%) among children 6 months to < 5 years and 66% (95% CI, 49%–77%) among children 5–17 years. VE was 53% (95% CI, 42%–62%) against any influenza-related ED visits, 46% (95% CI, 28%–60%) for A(H1N1)pdm09 and 54% (95% CI, 39%–66%) for B/Victoria. VE by age group was 52% (95% CI, 37%–63%) among children 6 months to < 5 years and 42% (95% CI, 16%–60%) among children 5–17 years.Table


Conclusion: Influenza vaccination in the 2019-20 season provided substantial protection against laboratory-confirmed influenza-associated hospitalizations and ED visits associated with the two predominantly circulating influenza viruses among children, including against the emerging B/Victoria virus V1A.3 subclade.

Presenting Author(s)

• 

  Angela P. Campbell, MD, MPH

  Medical Officer
  Centers for Disease Control and Prevention
  Atlanta, GA

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.

  Slides Slides and Audio

Co-Author(s)

• CO

  Constance E. Ogokeh, MPH

  Data Analyst
  Centers for Disease Control and Prevention
  Atlanta, Georgia

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• GW

  Geoffrey A. Weinberg, MD

  Professor
  University of Rochester
  Rochester, New York

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• JB

  Julie A. Boom, MD

  Associate professor
  Baylor College of Medicine and Texas Children's Hospital
  Houston, Texas

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• 

  Janet A. Englund, MD

  Professor
  Seattle Children's Hospital/Univ. of Washington
  Seattle, Washington

  Disclosure: AstraZeneca (Scientific Research Study Investigator)GSK group of companies (Scientific Research Study Investigator)Meissa vaccines (Consultant)Merck (Scientific Research Study Investigator)Sanofi Pasteur (Consultant)
• JW

  John V. Williams, MD

  Professor
  University of Pittsburgh
  Pittsburgh, Pennsylvania

  Disclosure: GlaxoSmithKline (Advisor or Review Panel member)IDConnect (Advisor or Review Panel member)Quidel (Advisor or Review Panel member)
• 

  Natasha B. Halasa, MD, MPH

  Associate Professor
  Vanderbilt University Medical Center
  Nashville, Tennessee

  Disclosure: Genentech : I receive an honorarium for lectures - it's a education grant, supported by genetech, Other Financial or Material Support; Karius : Consultant; Moderna : Consultant; Quidel : Grant/Research Support, Research Grant or Support; Sanofi : Grant/Research Support, Research Grant or Support
• RS

  Rangaraj Selvarangan, BVSc, PhD

  Director, Clinical Microbiology Laboratory
  Children's Mercy Hospital
  Kansas City, Missouri

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• MS

  Mary A. Staat, MD, MPH

  Professor
  Cincinnati Children's Hospital Medical Center
  Cincinnati, Ohio

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• EK

  Eileen J. Klein, MD, MPH

  Professor
  Seattle Children's Hospital
  Seattle, Washington

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• MM

  Monica McNeal, MS

  Co-investigator
  Cincinnati Children's Hospital Medical Center
  Cincinnati, Ohio

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• MM

  Marian G. Michaels, MD, MPH

  Professor
  UPMC Children's Hospital of Pittsburgh
  Pittsburgh, Pennsylvania

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• LS

  Leila C. Sahni, PhD, MPH

  Research Manager
  Texas Children’s Hospital
  Houston, Texas

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• LS

  Laura S. Stewart, PhD

  Program Manager
  Vanderbilt University Medical Center
  Nashville, Tennessee

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• PS

  Peter G. Szilagyi, MD, MPH

  Professor
  University of California, Los Angeles
  Los Angeles, California

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• CH

  Christopher J. Harrison, MD

  Professor
  The Children's Mercy Hospital- Kansas City
  Kansas City, Missouri

  Disclosure: GSK (Grant/Research Support, Infant menigiciccal B conjugate vaccine trial)Merck (Research Grant or Support, Infant pneumococcal conjugate vaccine trial)
• RH

  Robert Hickey, MD

  Professor
  Childrens Hospital of Pittsburgh
  Pittsburgh, Pennsylvania

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• BP

  Barbara Pahud, MD, MPH

  Associate Professor
  The Children's Mercy Hospital
  Kansas City, Missouri

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• 

  Jennifer E. Schuster, MD

  Assistant Professor
  Children's Mercy Hospital
  Kansas City, Missouri

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• GW

  Gina Weddle, DNP, RN, CPNP-AC/PC

  Director Advanced Practice Programs
  Children's Mercy Hospital
  Kansas City, Missouri

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• MM

  Mary Moffatt, MD

  Professor
  The Children's Mercy Hospital
  Kansas City, Missouri

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• JL

  Joana Y. Lively, MPH

  Epidemiologist
  Centers for Disease Control and Prevention
  Atlanta, Georgia

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• BR

  Brian Rha, MD, MSPH

  Medical Epidemiologist
  Centers for Disease Control and Prevention
  Atlanta, Georgia

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
• MP

  Manish Patel, MD

  Medical Officer
  Centers for Disease Control and Prevention
  Atlanta, Georgia

  Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.