Influenza and children
Influenza infection rates are generally highest in children. In a recent review of influenza hospitalisations in Australian children aged under 16 years over 2011–2013, previously healthy children accounted for 57% of admissions. Over the 2010–2016 influenza seasons in the U.S., 50% of children aged under 18 years who died with laboratory confirmed influenza (n= 327 of 654) were previously healthy. In Auckland during 2018, children aged under 5 years had the highest rate of hospitalisation with a severe acute influenza respiratory infection compared with other age groups, 281 cases per 100,000 people compared with 99/100,000 for adults aged 80 years or older, 47/100,000 for adults aged 65–79 years and 46/100,000 for midlife adults. Healthy children are also the major cause of the spread of influenza viruses in the community.
Vaccination of healthy children has the potential to substantially reduce influenza-like illness and related costs in both the children themselves and their families. Influenza vaccination recommendations vary between countries. The United States recommends annual vaccination for all persons from 6 months of age. The United Kingdom influenza vaccination programme includes annual vaccination for all children aged 2–9 years with a live attenuated nasal spray influenza vaccine with the strategy to offer both individual protection and herd immunity. This type of influenza vaccine is expected to be more effective in children but is not currently available in New Zealand.
New Zealand's current strategy
The current New Zealand strategy for children is to offer free influenza vaccination to those with certain medical conditions most likely to lead to serious influenza-related complications. For more information, please refer to the section Eligible conditions for funded influenza vaccination on page 6 of the Flu Kit Booklet 2019.
Children aged 6 months to under 9 years who are receiving the influenza vaccine for the first time should receive two doses four weeks apart. Children who have received a previous influenza vaccination need only a single dose.
|1 or 2*|
≥ 9 years
|INFLUVAC® TETRA||0.5 mLv||
1 or 2*
# A full 0.5 mL dose of FLUARIX® TETRA is administered for children aged 6–35 months.
* Two doses separated by at least four weeks if an influenza vaccine is being used for the first time.
Why does a child aged under 9 years need two doses if being vaccinated for the first time?
Children under 9 years of age who are receiving influenza vaccine for the first time have a better immune response after two priming doses of vaccine. This may be because they are more likely to be immunologically naive to influenza.
- Children needing two doses of influenza vaccine.
- Children who have received one influenza vaccine any time in the past only need a single dose in the current season.
Why does a child aged 6–35 months receive a full 0.5 mL dose of FLUARIX® TETRA?
The historical recommendations to use a half-dose of influenza vaccine in this age group related to older whole-cell influenza vaccines that caused strong vaccine responses such as fever. Current influenza vaccines are subunit vaccines that contain only viral surface antigens (haemagglutinin proteins). They are generally well tolerated by children in this age group. However, their ability to induce a robust immune response and protection from influenza is variable.
Receipt of a full 0.5 mL dose of inactivated influenza vaccine has the potential to improve protection against influenza. Clinical studies using a full 0.5 mL dose of the quadrivalent FLUARIX® TETRA vaccine in this age group have been conducted. These studies showed that receiving a full 0.5 mL dose of quadrivalent inactivated influenza vaccine was well tolerated by children in this age group, with vaccine responses comparable to those following either a full dose or a half dose inactivated trivalent influenza vaccine.
Use of paracetamol following vaccination
The routine prophylactic use of paracetamol or any other antipyretic to control fever either prior to or following vaccine administration is not recommended. Evidence shows that the laboratory measured immune response to some antigens can be reduced. However, there is no evidence that this causes individuals to be less protected from disease.
The current recommendations are as follows:
- Do not use routine prophylactic paracetamol pre- or post-vaccination in the absence of pain or significant discomfort.
- Infants who are uncomfortable with fever should first be managed with appropriate removal of clothing and other cooling measures such as cool drinks or tepid sponging.
- Use of paracetamol is recommended for relief of pain or significant discomfort post vaccination.
- Ibuprofen is less effective than paracetamol in managing post-vaccination pain or high fever and is not recommended.
NOTE: treatment advice may differ for other groups.
Anyone with concerns following vaccination should seek medical advice