influenza vaccine at a glance
Vaccine type
Live attenuated seasonal influenza vaccine.
Licensed age group
Children and adolescents aged 2 years to under 18 years.
Administration
Sprayed into both nostrils; normal breathing is sufficient and active sniffing is unnecessary.
Nasal blockage
Vaccination may be postponed if significant blockage could prevent effective delivery.
What is influenza vaccine used for?
Licensed use for Fluenz:
Preventing influenza in children and adolescents aged 2 years to under 18 years, in line with official recommendations.
How does influenza vaccine work?
Its weakened, cold-adapted influenza viruses replicate mainly in the cooler tissues of the nose. This prompts local and systemic immune responses against the included seasonal strains without causing clinical influenza.
How to take influenza vaccine
A trained healthcare professional administers Fluenz as a nasal spray. It must never be injected.
The spray is given into both nostrils while the recipient breathes normally.
Administration may be postponed for substantial nasal blockage; a mild cold without blockage does not usually require postponement.
Food and drink do not affect administration.
influenza vaccine side effects
Common or expected effects
- Blocked or runny nose
- Reduced appetite
- Feeling generally unwell
- Headache
- Muscle aches
- Fever
Get urgent medical advice
- Severe allergic reaction, including breathing difficulty or facial or tongue swelling
- Guillain–Barré syndrome has been reported, although its frequency is unknown
- Worsening symptoms in people with Leigh syndrome has been reported
influenza vaccine in pregnancy
Fluenz is not recommended during pregnancy because it is a live vaccine. UK guidance recommends an inactivated influenza vaccine instead. Discuss inadvertent Fluenz exposure with the relevant clinician.
influenza vaccine while breastfeeding
The Fluenz product information advises against use during breastfeeding because evidence is limited. Breastfeeding does not prevent use of an eligible inactivated influenza vaccine.
influenza vaccine interactions
Check current medicines and recent antiviral treatment before administering Fluenz.
Salicylates, including systemic aspirin
Fluenz is contraindicated during salicylate treatment. Salicylates should also be avoided afterwards unless medically necessary because of the theoretical risk of Reye’s syndrome.
Influenza antiviral medicines
These may reduce vaccine-virus replication and weaken the immune response, so administration timing requires clinical review.
Other vaccines
Fluenz may be given alongside specified live childhood vaccines. Follow product-specific and current programme guidance for other combinations.
Common questions about influenza vaccine
Answers are fully visible for fast scanning and source review.
Can Fluenz cause flu?
No. Its weakened, cold-adapted viruses cannot replicate efficiently at normal body temperature, although mild nasal symptoms or fever can occur.
Can a child with asthma have Fluenz?
Severe asthma or current wheezing makes Fluenz unsuitable. Other asthma circumstances require assessment against current programme guidance.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.