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Vaccine Pregnancy: §4.6: 'Inactivated influenza vaccines can be used in all stages of pregnancy. Larger datasets on safety are available for the second and third trimester, compared with the first trimester; however, data from worldwide use of influenza vaccine do not indicate any adverse fetal and maternal outcomes attributable to the vaccine.' Breast-feeding: 'Influenza vaccine TIV Viatris may be used during breast-feeding.' Fertility: 'No fertility data are available.'

Influenza vaccine (inactivated)

Brand names: Quadrivalent flu vaccines, Fluad (adjuvanted), Flucelvax (cell-based), Fluzone HD

The inactivated influenza vaccine provides active immunisation against seasonal influenza and is given annually, principally by intramuscular injection, to people in at-risk and eligible groups under the national programme.

Adult dose

Dose: 0.5 ml (one dose of Influenza vaccine TIV Viatris)
Route: Intramuscular or deep subcutaneous injection - 'The preferred sites for intramuscular injection are the anterolateral aspect of the thigh (or the deltoid muscle if muscle mass is adequate) in children 6 months through 35 months of age, or the deltoid muscle in children from 36 months of age and adults.' §4.4: the vaccine 'should under no circumstances be administered intravascularly'.
Frequency: A single 0.5 ml dose per course. THE RETRIEVED §4.2 STATES NO REVACCINATION INTERVAL and does not use the word 'annual' - the page's existing 'annually' is a national-programme statement (UK Green Book / JCVI), not a figure from this SPC, and is not published from this bundle.
SCOPE: this is one specific inactivated trivalent product. No age-related dose difference is given: adults and children from 6 months alike receive 0.5 ml. 'Infants less than 6 months of age: the safety and efficacy of Influenza vaccine TIV Viatris have not been established. No data are available.' Co-administration: 'If Influenza vaccine TIV Viatris is given at the same time as other vaccines, immunisation should be carried out on separate limbs. It should be noted that the adverse reactions may be intensified.' 'The immunological response may be diminished if the patient is undergoing immunosuppressant treatment.' 'Influenza vaccine TIV Viatris is not effective against all possible strains of influenza virus... As with any vaccine, a protective immune response may not be elicited in all vaccinees.'

Paediatric dose

Route: Intramuscular or deep subcutaneous injection - anterolateral aspect of the thigh (or the deltoid muscle if muscle mass is adequate) in children 6 months through 35 months of age; the deltoid muscle from 36 months of age.
Frequency: One 0.5 ml dose. 'Children less than 9 years of age, who have not previously been vaccinated with a seasonal influenza vaccine: a second dose of 0.5 ml should be given after an interval of at least 4 weeks.'
NOT A PER-KG DOSE - dosePerKg is deliberately null; the dose is a fixed volume at every age. §4.2, verbatim: 'Paediatric population Children from 6 months to 17 years of age: 0.5 ml.' The only paediatric variation is the second dose for under-9s not previously vaccinated (above). LOWER AGE LIMIT: 'Infants less than 6 months of age: the safety and efficacy of Influenza vaccine TIV Viatris have not been established. No data are available.' concentration is null because the bundle states no mg/ml content - an inactivated influenza vaccine is standardised by haemagglutinin content per strain, which the retrieved sections do not give - so no volume can be calculated from a mass.

Dose adjustments

Renal

Not stated - the retrieved sections contain no renal-impairment guidance.

Hepatic

Not stated - the retrieved sections contain no hepatic-impairment guidance.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substances, to any of the excipients listed in section 6.1 or to any component that may be present as traces such as eggs (ovalbumin, chicken proteins), formaldehyde, cetyltrimethylammonium bromide, polysorbate 80 or gentamicin
  • Febrile illness or acute infection - 'Immunisation shall be postponed in patients with febrile illness or acute infection'
  • Not a §4.3 contraindication but an absolute administration rule from §4.4: the vaccine 'should under no circumstances be administered intravascularly', and it should be given with caution to individuals with thrombocytopenia or any coagulation disorder 'since bleeding may occur following an intramuscular administration to these subjects'

Side effects

  • Most reactions occur within the first 3 days after vaccination and resolve spontaneously within 1 to 3 days of onset; intensity is generally mild
  • Vaccination site pain - the most frequently reported local reaction in all age groups (very common); other local reactions: redness, swelling, ecchymosis, induration
  • Adults: fatigue (very common) and headache (very common; reported as common in elderly adults >=61 years)
  • Children 6 to 17 years: fatigue and headache most frequent; children 3 to 5 years: drowsiness, irritability and loss of appetite; children 6 to 35 months: irritability/fussiness
  • Sweating (common in adults); myalgia and arthralgia; malaise and shivering; fever
  • Allergic reactions, in rare cases leading to shock or angioedema
  • Transient thrombocytopenia and transient lymphadenopathy
  • Neuralgia, paraesthesia, febrile convulsions and neurological disorders such as encephalomyelitis, neuritis and Guillain-Barre syndrome (post-marketing, frequency not known)
  • Vasculitis, associated in very rare cases with transient renal involvement
  • Generalised skin reactions including pruritus, urticaria or non-specific rash
  • NOTE ON THIS LIST: the §4.8 paediatric table is truncated at the source-fetch limit, so the paediatric frequencies above are those given in the summary-of-safety-profile paragraph rather than the full table.

Monitoring

  • Record the product name and batch number for every administration - §4.4 traceability requirement for biological medicinal products
  • Have appropriate medical treatment and supervision readily available in case of an anaphylactic event following administration
  • Observe for anxiety-related reactions - 'vasovagal reactions (syncope), hyperventilation or stress-related reactions can occur following, or even before, any vaccination... accompanied by several neurological signs such as transient visual disturbance, paraesthesia and tonic-clonic limb movements during recovery. It is important that procedures are in place to avoid injury from faints.'
  • Watch for bleeding at the injection site in patients with thrombocytopenia or a coagulation disorder
  • Interference with serological testing - 'Following influenza vaccination, false positive results in serology tests using the ELISA method to detect antibodies against HIV1, Hepatitis C and especially HTLV1 have been observed. The Western Blot technique disproves the false-positive ELISA test results.'

Clinical monograph

How it works

It contains inactivated influenza virus antigens, reformulated each season to match anticipated circulating strains, which stimulate strain-specific protective antibodies.

Prescribing in practice

  • Annual revaccination is required because circulating strains and antibody levels change, and the inactivated vaccine cannot cause influenza infection.
  • Defer in significant acute febrile illness, and review egg-allergy status as some inactivated products are egg-grown, choosing an appropriate product per current guidance.
  • Administer intramuscularly into the deltoid in adults, separating from other injections as advised.

Monitoring

No laboratory monitoring is needed; the patient should be observed briefly for immediate hypersensitivity after vaccination.

Counselling the patient

  • You need a flu vaccine every year to stay protected as the virus changes.
  • The injected vaccine is inactivated and cannot give you flu; a sore arm or mild fever can occur.
  • Tell the vaccinator about any serious egg allergy or previous vaccine reaction.

Evidence & guidelines

Annual inactivated influenza vaccination follows the eligible groups and product recommendations of the UK immunisation guidance (Green Book) and seasonal flu programme.

Reference: UK Green Book; JCVI; annual NHS flu letter; Confirm identity and dosing against the manufacturer SPC (eMC) and NICE. Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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