INFLUVAC^®

MIMS Revision Date: 01 February 2026

1 Name of Medicine

Trivalent influenza vaccine, surface antigen, inactivated (influenza virus haemagglutinin).

2 Qualitative and Quantitative Composition

Influvac is a purified, inactivated influenza vaccine (surface antigen), containing the following three influenza strains recommended for the 2026 influenza season:
A/Missouri/11/2025 (H1N1)pdm09-like virus (A/Switzerland/6849/2025, IVR-278);
A/Singapore/GP20238/2024 (H3N2)-like virus (A/Singapore/GP20238/2024, IVR-277);
B/Austria/1359417/2021 (B/Victoria lineage)-like virus (B/Austria/1359417/2021, BVR-26).
Each 0.5 mL dose contains 15 microgram haemagglutinin per each of the above mentioned viral strains, for a combined total amount of 45 micrograms. Each strain has been propagated in fertilised hens' eggs from healthy chickens.
The type and amount of viral antigens in Influvac conform to the requirements of the Australian Influenza Vaccine Committee (AIVC) and the New Zealand Ministry of Health for the 2026 southern hemisphere influenza season.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Influvac is a clear colourless liquid for injection in pre-filled syringes (glass, type I).

4 Clinical Particulars

4.1 Therapeutic Indications

For the prevention of influenza caused by influenza virus, types A and B.
For full details regarding recommendations for influenza vaccination, please refer to the relevant National Immunisation Guidelines.
Influvac is indicated in adults and children from 6 months of age and older.

4.2 Dose and Method of Administration

One dose is sufficient for persons previously exposed to viruses of similar antigenic composition to the strain(s) present in the vaccine. In those with some impairment of immune mechanisms, two doses separated by an interval of at least four weeks are recommended.
Adults and children 3 years of age and older. 0.5 mL.
Children from 6 months up to 35 months of age. Clinical data are limited. A 0.25 mL dose is recommended.
For children from 6 months up to 9 years of age who have not previously been vaccinated, a second dose may be given after an interval of at least four weeks.
The Australian Immunisation Handbook recommends that preterm infants should receive influenza vaccine every year, starting from 6 months of age and have a second dose at least 4 weeks later if receiving influenza vaccine for the first time.
Children less than 6 months of age. The safety and efficacy of Influvac has not been established.
Influvac should be administered in autumn before the beginning of the influenza season or as required by the epidemiological situation. Vaccination should be repeated every year with an age appropriate dose of vaccine of updated antigen composition.
Administration. Influvac should be administered by intramuscular or deep subcutaneous injection. Influvac should not be administered intravenously.
Influvac should not be mixed with other injection fluids.
Data on the administration of Influvac with other vaccines is not available.
For administration of a 0.25 mL dose from a syringe, push the front side of the plunger exactly to the edge of the mark so that half of the volume is eliminated; a reproducible volume of vaccine remains in the syringe suitable for administration.
The syringe is for use in a single patient on one occasion only. Remaining contents should be discarded.
Instructions for use/handling. Influvac should be allowed to reach room temperature, shaken well and inspected visually before use.

4.3 Contraindications

Hypersensitivity to the active substances, or to any component of the vaccine, except egg proteins (see Section 2 Qualitative and Quantitative Composition; Section 6.1 List of Excipients). See Section 4.4 Special Warnings and Precautions for Use for vaccination in individuals with a known egg allergy.
Anaphylaxis following a previous dose of any influenza vaccine.
Immunisation should be postponed in patients with an acute febrile illness.
The presence of a minor illness with or without fever should not contraindicate the use of Influvac.
Refer to the relevant National Immunisation Guidelines for full details on contraindications and precautions.

4.4 Special Warnings and Precautions for Use

As with all injectable vaccines, appropriate medical treatment and supervision should always be readily available in case of a rare anaphylactic event following the administration of the vaccine.
Influvac is required to contain no more than 1 microgram ovalbumin per dose. People with egg allergy, including a history of anaphylaxis, can be safely vaccinated unless they have reported a serious adverse reaction to influenza vaccines. Egg allergy does not increase the risk of anaphylaxis but anaphylaxis to other components may occur. Refer to the current Australian Immunisation Handbook for guidance on the use of influenza vaccines in individuals with egg allergy.
Influvac should under no circumstances be administered intravascularly.
As with other vaccines administered intramuscularly, Influvac should be given with caution to individuals with thrombocytopenia or any coagulation disorder since bleeding may occur following an intramuscular administration to these subjects.
Patients with impaired immune responsiveness, whether due to the use of immunosuppressive therapy, a genetic defect, human immunodeficiency virus (HIV) infection, or other causes, may have a reduced antibody response in active immunisation procedures.
Patients with a history of Guillain-Barre syndrome (GBS) with an onset related in time to influenza vaccination may be at increased risk of again developing GBS if given influenza vaccine. While this risk should be weighed against the benefits to the individual patient of influenza vaccination, it would seem prudent to avoid subsequent influenza vaccination in this group. Because patients with a history of GBS have an increased likelihood of again developing the syndrome, the chance of them coincidentally developing the syndrome following influenza vaccination may be higher than in individuals with no history of GBS.
Anxiety-related reactions, including vasovagal reactions (syncope), hyperventilation or stress related reactions can occur following, or even before, any vaccination as a psychogenic response to the needle injection. This can be 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.
Influvac is not effective against all possible strains of influenza virus. Influvac is intended to provide protection against those strains of virus from which the vaccine is prepared and to closely related strains.
As with any vaccine, a protective immune response may not be elicited in all vaccinees.
Antibody response in patients with endogenous or iatrogenic immunosuppression may be insufficient.
This medicine contains sodium, less than 1 mmol (23 mg) per dose, i.e. essentially 'sodium free'.
This medicine contains potassium, less than 1 mmol (39 mg) per dose, i.e. essentially 'potassium free'.
Paediatric use. Use in children younger than 6 months. The safety and efficacy of Influvac in children younger than 6 months have not been established. No data are available.
Effects on laboratory tests. 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 results. The transient false positive reactions could be due to the IgM response by the vaccine.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Influenza vaccine can impair the metabolism of warfarin, theophylline, phenytoin, phenobarbitone and carbamazepine by the hepatic P450 system. Results from studies have been variable in degree of interaction and time after vaccination for the interaction to take effect. The interaction may be idiosyncratic. Patients taking warfarin, theophylline, phenytoin, phenobarbitone, or carbamazepine should be advised of the possibility of an interaction and told to look out for signs of elevated levels of medication.
Influvac should not be mixed with other vaccines in the same syringe.
No interaction studies have been performed. If Influvac 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.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility. No animal or human fertility data are available.
Use in pregnancy. (Category B2)
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 or maternal outcomes attributable to the vaccine.
Health authorities recommend vaccination for all pregnant women at any stage of pregnancy, particularly those who will be in the second or third trimester during the influenza season.
Use in lactation. Influvac may be used during lactation.

4.7 Effects on Ability to Drive and Use Machines

Influvac has no or negligible influence on the ability to drive and use machines.

4.8 Adverse Effects (Undesirable Effects)

The most frequently reported adverse drug reactions following use of Influvac are local and/or systemic reactions such as injection site pain or fatigue and headache.
Most of these adverse reactions are of mild to moderate intensity.
These reactions usually disappear within 1-2 days without treatment.
In rare cases, allergic reactions may evolve to shock, angioedema (see Section 4.4 Special Warnings and Precautions for Use).
The events are categorised by frequency according to the following definitions: very common (frequency ≥ 10%); common (frequency ≥ 1 and < 10%); uncommon (frequency ≥ 0.1% and < 1%); rare (frequency ≥ 0.01% and < 0.1%); very rare (frequency < 0.01%).
Local reactions. Very common: redness, swelling, pain.
Common: ecchymosis, induration.
Body as a whole. Very common: headache.
Common: fever, malaise.
Uncommon: shivering, fatigue, sweating, myalgia, arthralgia.
Very rare: neuralgia, paraesthesia, convulsions, transient thrombocytopenia, allergic reactions (such as angioedema) leading to shock.
As with most biological products, very rare post-vaccination neurological disorders such as encephalomyelitis, neuritis and Guillain-Barre syndrome (GBS) have been reported. Guillain-Barre syndrome (GBS) has been very rarely reported in temporal association with administration of influenza vaccines. In the 1976 swine influenza vaccination program, the US Public Health Advisory Committee on Immunization Procedures (ACIP) found that GBS occurred at an incidence of approximately 1 in 100,000 after immunisation and that the death rate in this 'series' was approximately 1 in 2,000,000. Such an excess incidence of GBS was not demonstrated in subsequent years when recipients of the 1978 or 1979 vaccines were studied. However, in 1998, ACIP reported that a study of the 1992-93 and 1993-94 seasons found an elevation in the overall relative risk for GBS which represents an excess of an estimated one to two cases of GBS per million persons vaccinated.
Post-marketing experience. Adverse reactions reported from post marketing surveillance are, next to the reactions which have also been observed during the clinical trials, the following:
Blood and lymphatic system disorders. Transient thrombocytopenia, transient lymphadenopathy.
Immune system disorders. Allergic reactions, in rare cases leading to shock, angioedema.
Nervous system disorders. Neuralgia, paraesthesia, febrile convulsions, neurological disorders, such as encephalomyelitis, neuritis and Guillain Barre syndrome.
Vascular disorders. Vasculitis associated in very rare cases with transient renal involvement.
Skin and subcutaneous tissue disorders. Generalised skin reactions including pruritus, urticaria or non-specific rash.
Reporting suspected adverse effects. Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at www.tga.gov.au/reporting-problems.

4.9 Overdose

Given the nature of the product and mode of administration the probability of over dosage is negligible.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action. The vaccine stimulates production of antibodies with a specific capacity against influenza. Protection is only against those strains of the virus from which the vaccine is prepared or closely related strains.
Seroprotection is obtained within 2-3 weeks. The duration of post-vaccination immunity varies between 6-12 months.

5.2 Pharmacokinetic Properties

Not applicable.

5.3 Preclinical Safety Data

Genotoxicity. No genotoxicity studies have been conducted with Influvac.
Carcinogenicity. No carcinogenicity studies have been conducted with Influvac.

6 Pharmaceutical Particulars

6.1 List of Excipients

Each 0.5 mL dose contains 0.10 mg potassium chloride, 0.10 mg monobasic potassium phosphate, 0.67 mg dibasic sodium phosphate dihydrate, 4.0 mg sodium chloride, 0.067 mg calcium chloride dihydrate, 0.05 mg magnesium chloride hexahydrate and q.s. to 0.5 mL water for injections.
Influvac antigens have been produced from eggs and are inactivated by formaldehyde treatment. Each 0.5 mL may also contain not more than 100 nanogram ovalbumin, 0.01 mg formaldehyde, 0.015 mg cetrimonium bromide, 1 mg sodium citrate, 0.2 mg sucrose, 1 nanogram gentamicin sulfate, trace amounts of chicken proteins, traces of tylosin tartrate, hydrocortisone and polysorbate 80, which are used during the manufacturing process.

6.2 Incompatibilities

In the absence of compatibility studies, this medicinal product must not be mixed with other medicinal products.
See Section 4.5 Interactions with Other Medicines and Other Forms of Interactions.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Keep out of the sight and reach of children.
Store between 2 and 8 degrees Celsius. Refrigerate, do not freeze. Store in the original package in order to protect from light.

6.5 Nature and Contents of Container

Single-dose 0.5 mL pre-filled glass syringe, 1's and 10's.
Some strengths, pack sizes and/or pack types may not be marketed.
Australian register of therapeutic goods (ARTG). AUST R 432790 - Influvac influenza virus haemagglutinin 0.5 mL vaccine prefilled syringe with 16 mm needle.
AUST R 432810 - Influvac influenza virus haemagglutinin 0.5 mL vaccine prefilled syringe with 25 mm needle.
AUST R 432811 - Influvac influenza virus haemagglutinin 0.5 mL vaccine prefilled syringe without needle.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of in accordance with local requirements.

6.7 Physicochemical Properties

Not applicable.

7 Medicine Schedule (Poisons Standard)

S4 (Prescription Only Medicine).

Date of First Approval

21 January 2025

Date of Revision

05 November 2025

Summary Table of Changes