Influenza Vaccine Effectiveness and Uptake in Children at Risk of Severe Disease

Christopher C Blyth1, Peter Jacoby, Paul V Effler

  • 1From the *School of Paediatrics and Child Health, University of Western Australia; †Department of Infectious Diseases, Princess Margaret Hospital for Children; ‡Wesfarmers Centre for Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia; §Department of Microbiology, PathWest Laboratory Medicine WA, Princess Margaret Hospital for Children; ¶Department of Health, Communicable Disease Control Directorate, Perth, Western Australia, Australia; ‖Victorian Infectious Diseases Reference Laboratory, Melbourne, Australia; **Australian National University, Canberra, Australia; ††School of Pathology and Laboratory Medicine, University of Western Australia; ‡‡Department of Microbiology, QEII Medical Centre, PathWest Laboratory Medicine WA; §§Emergency Department, Princess Margaret Hospital for Children; ¶¶School of Primary, Aboriginal and Rural Health Care, University of Western Australia; and ‖‖Department of General Paediatrics, Princess Margaret Hospital for Children, Perth, Western Australia, Australia.

Insights

The inactivated trivalent influenza vaccine (TIV) demonstrated high vaccine effectiveness (VE) of at least 70% in young children, including those with risk factors for severe disease. However, uptake remains low due to parental and prescriber concerns about TIV safety and benefits.

Area of Science:

  • Pediatric Infectious Diseases
  • Vaccinology
  • Public Health

Background:

  • Limited data exist on the effectiveness of inactivated trivalent influenza vaccine (TIV) in high-risk children.
  • This study aimed to determine TIV effectiveness in children with risk factors for severe influenza and compare vaccination attitudes.

Observation:

  • A test-negative design study included 2,723 children aged 6-59 months with influenza-like illness from 2008-2014.
  • Risk factors identified included comorbid medical conditions, preterm birth, and indigeneity.
  • Influenza was detected in 20.1% of participants.

Findings:

  • Overall TIV vaccine effectiveness (VE) was 70.0%, with VE of 82.5% for children with medical comorbidities, 79.2% for preterm infants, and 84.7% for children under 2 years.
  • Vaccine uptake declined significantly after 2010, affecting both high-risk and low-risk children.
  • Parental attitudes and prescriber recommendations were similar between children with and without risk factors.

Implications:

  • TIV demonstrates significant protection against influenza in young children, including vulnerable populations.
  • Low vaccination program participation highlights a need to address parental and prescriber hesitancy regarding TIV safety and efficacy.
  • Improved communication strategies are needed to boost influenza vaccination rates in children.
Abstract