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Safety and immune responses in children after concurrent or sequential 2009 H1N1 and 2009-2010 seasonal trivalent

Sharon E Frey1, David I Bernstein, Michael A Gerber

  • 1Division of Infectious Diseases, Allergy and Immunology, Saint Louis University School of Medicine, St. Louis, MO 63104, USA. freyse@slu.edu

The Journal of Infectious Diseases
|July 18, 2012
PubMed

Insights

In 2009, children received either one or two doses of the monovalent 2009 H1N1 influenza vaccine (2009 H1N1 vaccine) alongside the seasonal trivalent inactivated influenza vaccine (TIV). The study found that vaccine combinations were safe and generally well-tolerated across all age groups.

Area of Science:

  • Immunology
  • Vaccinology
  • Pediatrics

Background:

  • Seasonal and pandemic influenza vaccines were administered separately in 2009.
  • A randomized trial was conducted to evaluate combined influenza vaccine administration in children.

Purpose of the Study:

  • To assess the safety and immunogenicity of sequential or concurrent administration of 2009 H1N1 influenza vaccine and seasonal trivalent inactivated influenza vaccine (TIV) in children.
  • To determine optimal dosing of the 2009 H1N1 vaccine based on age.

Main Methods:

  • A randomized trial involving 531 children stratified by age.
  • Four study groups received different combinations of one dose of TIV and two doses of 2009 H1N1 vaccine.
  • Hemagglutination inhibition antibody responses, reactogenicity, and adverse events were monitored.

Main Results:

  • All vaccine combinations were safe and generally well-tolerated.
  • One dose of 2009 H1N1 vaccine and one dose of TIV were immunogenic in children aged 10 years and older.
  • Children younger than 10 years required two doses of the 2009 H1N1 vaccine for an adequate immune response.

Conclusions:

  • The sequence of vaccine administration did not impact 2009 H1N1 vaccine immunogenicity but affected TIV antibody titers.
  • Two doses of the 2009 H1N1 vaccine were necessary for protective immunity in children under 10.
  • Combined influenza vaccination strategies were safe and effective in pediatric populations.
Abstract

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