Effectiveness of Influenza Vaccine Against Life-threatening RT-PCR-confirmed Influenza Illness in US Children, 2010–2012
- Jill M. Ferdinands1,2,
- Lauren E. W. Olsho3,
- Anna A. Agan4,
- Niranjan Bhat5,
- Ryan M. Sullivan4,
- Mark Hall6,
- Peter M. Mourani7,
- Mark Thompson1 and
- Adrienne G. Randolph4
- on behalf of the Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network
- 1Influenza Division, US Centers for Disease Control and Prevention
- 2Battelle Memorial Institute, Atlanta, Georgia
- 3Abt Associates, Inc., Cambridge
- 4Department of Anesthesia, Perioperative and Pain Medicine (Critical Care), Boston Children's Hospital, Massachusetts
- 5Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- 6Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, Ohio
- 7Section of Critical Care Medicine, Department of Pediatrics, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora
- Correspondence: Jill M. Ferdinands, PhD, US Centers for Disease Control and Prevention, 1600 Clifton Rd NE, MS A-20, Atlanta, GA 30333 (jferdinands{at}cdc.gov).
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Previous presentation: This study and its findings reported herein were presented at the Infectious Diseases Society of America annual meeting on 3 October 2013.
Abstract
Background. No studies have examined the effectiveness of influenza vaccine against intensive care unit (ICU) admission associated with influenza virus infection among children.
Methods. In 2010–2011 and 2011–2012, children aged 6 months to 17 years admitted to 21 US pediatric intensive care units (PICUs) with acute severe respiratory illness and testing positive for influenza were enrolled as cases; children who tested negative were PICU controls. Community controls were children without an influenza-related hospitalization, matched to cases by comorbidities and geographic region. Vaccine effectiveness was estimated with logistic regression models.
Results. We analyzed data from 44 cases, 172 PICU controls, and 93 community controls. Eighteen percent of cases, 31% of PICU controls, and 51% of community controls were fully vaccinated. Compared to unvaccinated children, children who were fully vaccinated were 74% (95% CI, 19% to 91%) or 82% (95% CI, 23% to 96%) less likely to be admitted to a PICU for influenza compared to PICU controls or community controls, respectively. Receipt of 1 dose of vaccine among children for whom 2 doses were recommended was not protective.
Conclusions. During the 2010–2011 and 2011–2012 US influenza seasons, influenza vaccination was associated with a three-quarters reduction in the risk of life-threatening influenza illness in children.
Key words
- case-control studies
- child
- influenza vaccines
- intensive care
- respiratory failure
- influenza infection
- Received November 14, 2013.
- Accepted February 13, 2014.
- Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.
