Key points

  • Children under 5 years of age are at increased risk of severe influenza infections and death.
  • Influenza vaccination of young children has been shown to be safe and effective.
  • Influenza vaccination of young children not only protects this vulnerable age-group but is also an important way to reduce influenza transmission to other vulnerable groups.

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Background

The National Health and Medical Research Council recommends annual vaccination for individuals 6 months or older who wish to reduce their chances of becoming ill with influenza1.

Infants and children younger than 5 years of age are at high risk of getting severe influenza infections that require hospitalisation. Around 10% of hospitalised infants and children need care in an intensive care unit, and some, even previously healthy children, will die.

The NSW Government provides free influenza vaccination for all children aged 6 months to under 5 years2. Children aged over 5 years who have high risk medical conditions are also eligible for vaccination under the National Immunisation Program3.

Burden of illness

 In Australia, more children aged under 5 are hospitalised with influenza than any other vaccine preventable disease4.

The annual hospitalisation rate attributable to influenza for children aged under 5 is 105 per 100,000 children5. This increases to 192 per 100,000 for children aged 0-5 months6.

While children with underlying health problems are at higher risk, healthy children are also at risk. One study found 57% of Australian children admitted to hospital with influenza were otherwise healthy7.

An Australian review of the 2015 influenza season at two major hospitals found 7.3% of children admitted with confirmed influenza needed intensive care8. Only 12% of the children had received a seasonal influenza vaccine.

A 6-year study of influenza in the US found the highest incidence of influenza-related deaths were in children aged under 6 months and those aged 6-23 months (0.66 and 0.33 per 100 000 children respectively)9. In the 2010-2011 season nearly half of the children who died were otherwise healthy10.

Effectiveness

Protection of children

International studies have documented the effectiveness of immunising healthy young children against influenza. One European study in 2008 found a 66% vaccine efficacy (VE) against confirmed influenza for children aged 9 months to 3 years11, while a Japanese study of children aged 6 months to 6 years found VE against influenza A ranged from 42% to 69% depending on the vaccine match, and estimated one influenza A hospitalisation was prevented for each 71 children vaccinated12.

Recent NSW and Australian studies have also demonstrated relatively high vaccine effectiveness among previously healthy children13, particularly for children aged under 2 years14, and also among children at risk of severe disease15.

Indirect protection

One indirect way to protect vulnerable people, such as infants less than 6 months of age, those with compromised immune systems and older adults, is to increase influenza vaccination coverage in children.

Influenza vaccination programs for children have been shown to significantly reduce influenza-related disease and death in older adults as well as reduce rates of influenza-like illness in children16-18.

There is consistent evidence of influenza vaccination in children providing indirect protection of unvaccinated persons at the household and population level, from both randomised trials and ecological studies19.

Safety

Fever and injection site reactions are expected mild adverse reactions following immunisation. The current vaccine safety surveillance program which links provider and parent vaccine adverse event reporting with jurisdictional health departments and the Therapeutic Goods Administration, and active surveillance by AusVaxSafety at the National Centre for Immunisation Research and Surveillance, provides reassurance that the influenza vaccines used in children continue to be safe20-22.

Febrile seizures after influenza vaccination can occur although this is uncommon, occurring at a rate of 1 or less per 1,000 vaccinated children up to 6 years of age23. Parents should be made aware of the possibility and the child should be monitored for fever. Paracetamol or tepid water sponging can be used to reduce fever.

The safety of influenza vaccine in children – both those with and without high-risk medical conditions – will continue to be closely monitored.

Influenza vaccine and febrile seizures in children in WA

The 2010 Southern Hemisphere formulation of the trivalent influenza vaccine Fluvax® (CSL) was associated with an increase in the rate of febrile seizures and this was particularly notable in Western Australia due to their universal influenza vaccination program for children24. This problem was limited to a single brand’s manufacturing processes.

In 2019, the current version of this product, Afluria® Quad (now a quadrivalent vaccine) is indicated for use only in persons aged 5 years and over. It must not be used in persons under 5 years 25.

Influenza immunisation for children

 Influenza vaccines recommended for use in children in Australia are:

  • FluQuadri Junior® for children aged 6 months-35 months (less than 3 years)
  • FluQuadri® for children aged 3 years and over
  • Fluarix Tetra® for children aged 6 months and over
  • Afluria Quad® for children aged 5 years and over.

Note that no influenza vaccines are licenced for use in children less than 6 months of age however, vaccination during pregnancy provides protection to infants in the early months of life26.

First year of receiving the influenza vaccine

Children aged 6 months to under 9 years receiving influenza vaccine for the first time require 2 doses of an age-appropriate vaccine one month apart to maximise the immune response to the vaccine strains.

Subsequent years

Children who have previously received 1 or more doses of a trivalent or quadrivalent influenza vaccine require only 1 dose of an age-appropriate influenza vaccine for all seasons thereafter.

Vaccine providers should ensure that all influenza vaccinations administered to children are recorded in the Australian Immunisation Register (AIR) under the specific brand name used.

Influenza vaccines for children in NSW

Refer to the Seasonal Influenza Vaccination information.

References

  1. Australian Technical Advisory Group on Immunisation (ATAGI). The Australian immunisation handbook 10th ed (2017 update). Canberra: Australian Government Department of Health, 2017.
  2. Free flu shots for children aged 6 months to under 5 years, NSW Health. (accessed 26 March 2018).
  3. Commonwealth Department of Health and Ageing. National Immunisation Program Schedule (accessed 11 May 2018).
  4. Brotherton J, Wang H, Schaffer A, et al. Vaccine preventable diseases and vaccination coverage in Australia, 2003 to 2005. Communicable Diseases Intelligence 2007; 31(Suppl).
  5. Newall A, Scuffham P. Influenza-related disease: The cost to the Australian healthcare system. Vaccine 2008; 26: 6818–6823.
  6. Li-Kim-Moy J, Yin J, Patel C, et al. Australian vaccine preventable disease epidemiological review series: Influenza 2006 to 2015; Communicable Diseases Intelligence 2016, 40(4).
  7. Li-Kim-Moy J, Yin JK, Blyth CC, et al. Influenza hospitalizations in Australian children. Epidemiology and Infection 2017;145:1451-60.
  8. McRae J, Quinn H, Macartney et al. Paediatric active enhanced disease surveillance (PAEDS) annual report 2015: Prospective hospital-based surveillance for serious paediatric conditions. Communicable Diseases Intelligence 2017, 41(3).
  9. Shang M, Blanton L, Brammer L, et al. Influenza-associated pediatric deaths in the United States, 2010–2016. Pediatrics. 2018; 141(4).
  10. CDC. Influenza-Associated Pediatric Deaths - United States, September 2010–August 2011. MMWR Morb Mortal Wkly Rep 2011; 60: 1233-1238.
  11. Heinonen S, Silvennoinen H, Lehtinen P, et al. Effectiveness of inactivated influenza vaccine in children aged 9 months to 3 years: an observational cohort study. Lancet Infect Dis. 2011; 11(1): 23-29.
  12. Katayose M, Hosoya M, Haneda T, et al. The effectiveness of trivalent inactivated influenza vaccine in children over six consecutive influenza seasons. Vaccine 2011; 29(9): 1844-9. Epub 2010 Dec 31.
  13. Blyth C, Macartney K, Hewagama S, et al. Influenza epidemiology, vaccine coverage and vaccine effectiveness in children admitted to sentinel Australian hospitals in 2014: The Influenza Complications Alert Network (FluCAN). Euro Surveill. 2016; 21(30): pii=30301.
  14. Blyth CC, Jacoby P, Effler PV, et al. Effectiveness of Trivalent Flu Vaccine in Healthy Young Children. Pediatrics 2014;133:e1218-25.
  15. Blyth C, Jacoby P, Effler P, et al. Influenza vaccine effectiveness and uptake in children at risk of severe disease. Pediatr Infect Dis J 2016; 35: 309–315.
  16. Reichert T, Sugaya N, Fedson D, et al. The Japanese experience with vaccinating schoolchildren against influenza. N Engl J Med 2001; 344: 889–896.
  17. Sugaya N, Takeucki Y. Mass vaccination of schoolchildren against influenza and its impact on the influenza-associated mortality rate among children in Japan. Clin Infect Dis 2005; 41: 939–947.
  18. Ghendon Y, Kaira A, Elshina G. The effect of mass influenza immunization in children on the morbidity of the unvaccinated elderly. Epidemiol Infect 2006; 134: 71–78.
  19. Yin J, Heywood A, Georgousakis M, et al. Systematic review and meta-analysis of indirect protection afforded by vaccinating children against seasonal influenza: implications for policy. Clin Inf Dis 2017; 65(5): 719–28.
  20. Therapeutic Goods Administration. 2018 seasonal influenza vaccines (accessed 11 April 2018).
  21. AusVaxSafety (accessed 11 April 2018).
  22. Pillsbury A, Quinn H, Cashman P, et al. Active SMS-based influenza vaccine safety surveillance in Australian Children. Vaccine 2017; 35(51):7101-7106.
  23. Li-Kim-Moy J, Yin J, Rashid H, et al. Systematic review of fever, febrile convulsions and serious adverse events following administration of inactivated trivalent influenza vaccines in children. Eurosurveillance 2015; 20(24):pii=21159.
  24. Therapeutic Goods Administration. Seasonal flu vaccine: Investigation into febrile reactions in young children following 2010 seasonal trivalent influenza vaccination. Canberra: TGA; 2010 .
  25. Therapeutic Goods Administration. Consumer Medicine Information (AUST R 262428 and AUST R 294907) - Afluria® Quad .
  26. Refer to the NSW Health Maternal influenza vaccination - evidence review .
Page Updated: Thursday 9 May 2019
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