Influvac

Leaflet accompanying the packaging: information for the user

Influvac, suspension for injection in a pre-filled syringe

Influenza vaccine (surface antigen, inactivated)
Season 2025/2026

Read the leaflet carefully before the vaccine is given to an adult or child, as it contains important information for the patient.

• Keep this leaflet, you may need to read it again.
• If you have any further questions, ask your doctor, pharmacist, or nurse.
• This vaccine has been prescribed specifically for the adult or child. Do not pass it on to others.
• If the adult or child experiences any side effects, including any not listed in this leaflet, please tell your doctor, pharmacist, or nurse. See section 4.

Table of contents of the leaflet

• 1. What is Influvac and what is it used for
• 2. Important information before Influvac is given to an adult or child
• 3. How to use Influvac
• 4. Possible side effects
• 5. How to store Influvac
• 6. Contents of the pack and other information

1. What is Influvac and what is it used for

Influvac is a vaccine for adults and children from 6 months of age. The vaccine helps protect adults and children from catching flu. The use of Influvac should be in line with official recommendations.
After vaccination with Influvac, the body's immune system (the body's natural defense system) produces its own defense (antibodies) against the disease. None of the vaccine components cause flu.
Flu is a disease that can spread quickly. It is caused by different strains of the virus, which can change every year. For this reason, vaccination of an adult or child may be necessary every year. The greatest risk of catching flu is in the cold months between October and March. If an adult or child has not been vaccinated in the autumn, it is still justified to get vaccinated until spring, as there is still a risk of catching flu. The doctor will determine the best time for vaccination.
Influvac protects adults and children against the three virus strains contained in the vaccine about 2-3 weeks after vaccination.
The incubation period of flu in the body is a few days, so if an adult or child comes into contact with the virus shortly before or shortly after vaccination, there is a possibility of catching flu.
The vaccine does not protect adults or children from catching a cold, even though some of its symptoms are similar to those of flu.

2. Important information before Influvac is given to an adult or child

To ensure that Influvac is the right vaccine for the patient, tell your doctor, pharmacist, or nurse if any of the following apply to the adult or child who is to receive the vaccine.
If you are unsure, ask your doctor, pharmacist, or nurse to explain.

When not to use Influvac

• if the adult or child is allergic (hypersensitive) to:
• the active substances or
• any of the other ingredients of Influvac (see section 6) or
• any of the ingredients that may be present in very small amounts, such as chicken eggs (egg albumen, chicken proteins), formaldehyde, trimethoxycetyl bromide, polysorbate 80, or gentamicin (an antibiotic used to treat bacterial infections)

Warnings and precautions

Tell your doctor if the adult or child has:

• weakened immune response (due to immune deficiency or taking medicines that affect the immune system)
• bleeding or bruising easily

Your doctor will decide if the adult or child can be vaccinated.
If the adult or child has a disease with high fever or acute infection, vaccination should be postponed until recovery.
Fainting, feeling faint or weak, or other stress-related reactions can occur before or after any injection. If the patient has had such a reaction before, they should tell their doctor or nurse.
Tell your doctor if the adult or child is scheduled to have blood tests within a few days of vaccination against flu. In some patients, false-positive blood test results have been observed shortly after flu vaccination.
Like all vaccines, Influvac may not fully protect all vaccinated patients.

Influvac and other medicines

• Tell your doctor, pharmacist, or nurse about all vaccines or medicines the adult or child is taking or has recently taken, as well as any medicines the patient plans to take, including those available without a prescription.
• Influvac can be given at the same time as other vaccines, but each vaccine should be given in a different limb. Concurrent administration of vaccines may increase side effects.
• Immune response may be weakened in patients taking medicines that reduce the immune response, such as corticosteroids, cytotoxic drugs, or radiation therapy.

Pregnancy and breastfeeding

If the patient is pregnant or breastfeeding, or thinks they may be pregnant or plans to become pregnant, they should consult their doctor before receiving this vaccine.
Flu vaccines can be used at any stage of pregnancy. A larger dataset on the safety of the vaccine during pregnancy is available for the second and third trimesters compared to the first trimester, and data on flu vaccines from around the world do not indicate that the vaccine has any harmful effects during pregnancy or to the fetus.
Influvac can be used during breastfeeding.
The doctor, pharmacist, or nurse will decide whether the pregnant woman can be vaccinated with Influvac. Before taking any medicine, consult your doctor, pharmacist, or nurse.

Driving and using machines

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

Influvac contains sodium and potassium

The vaccine contains less than 1 mmol of sodium (23 mg) per dose, which means it is "sodium-free".
The vaccine contains less than 1 mmol of potassium (39 mg) per dose, which means it is "potassium-free".

3. How to use Influvac

Dosage

Adults receive one dose of 0.5 ml.

Use in children and adolescents

Children from 6 months to 17 years of age receive one dose of 0.5 ml.
Children under 9 years of age who have not been previously vaccinated or have not been fully vaccinated with a seasonal flu vaccine: a second dose of 0.5 ml should be given at least 4 weeks apart.
Children under 6 months of age: the safety and efficacy of Influvac have not been established.

Method and route of administration

The vaccine is given by a doctor or nurse intramuscularly or deep subcutaneously.
If you have any doubts about the use of the vaccine, ask your doctor, pharmacist, or nurse.

4. Possible side effects

Like all medicines, Influvac can cause side effects, although not everybody gets them.

In case of the following side effects, the adult or child should see a doctor immediately – immediate medical attention may be required:

Severe allergic reactions (frequency not known, reported sporadically with Influvac)

• rarely, may require immediate medical attention, with symptoms of circulatory failure to maintain blood flow to various organs (shock)
• very rarely, swelling, most pronounced in the head and neck area, including the face, mouth, tongue, throat, or other parts of the body, which can cause difficulty swallowing or breathing (angioedema).

During clinical trials with Influvac and/or the quadrivalent vaccine Influvac Tetra, the following side effects were observed. Their frequency is:

• very common (may affect more than 1 in 10 people);
• common (may affect up to 1 in 10 people);
• uncommon (may affect up to 1 in 100 people); and
• frequency not known (side effects from post-marketing experience; cannot be estimated from available data)

In all age groups, most of the above side effects occurred within the first 3 days of vaccination and resolved on their own within 1 to 3 days of onset. Generally, they were mild.

Reporting side effects

If you experience any side effects, including any not listed in this leaflet, please tell your doctor, pharmacist, or nurse. Side effects can be reported directly to the Department of Drug Safety, Office for Registration of Medicinal Products, Medical Devices, and Biocidal Products:
Jerozolimskie Avenue 181C
02-222 Warsaw
tel.: +48 22 49 21 301
fax: +48 22 49 21 309
website: https://smz.ezdrowie.gov.pl
Side effects can also be reported to the marketing authorization holder.
By reporting side effects, you can help provide more information on the safety of this medicine.

5. How to store Influvac

Keep the vaccine out of the sight and reach of children.
Do not use this vaccine after the expiry date stated on the carton and on the syringe after EXP. The expiry date refers to the last day of that month.
Store in a refrigerator (2°C - 8°C). Do not freeze.
Store the pre-filled syringe in the outer carton to protect from light.
Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. This will help protect the environment.

6. Contents of the pack and other information

What Influvac contains

The active substances are:
Influenza surface antigens (hemagglutinin and neuraminidase) corresponding to the following strains*:
A/Victoria/4897/2022 (H1N1)pdm09-like strain (A/Victoria/4897/2022, IVR-238)
15 micrograms of HA**
A/Croatia/10136RV/2023 (H3N2)-like strain (A/Croatia/10136RV/2023, X-425A)
15 micrograms of HA**
B/Austria/1359417/2021-like strain (B/Austria/1359417/2021, BVR-26)
15 micrograms of HA**
per 0.5 ml dose
* grown in chicken embryos from healthy flocks
** hemagglutinin
This vaccine is in line with the recommendations of the World Health Organization (WHO) (for the Northern Hemisphere) and EU recommendations for the 2025/2026 season.
The other ingredients of the vaccine are: potassium chloride, potassium dihydrogen phosphate, disodium phosphate dihydrate, sodium chloride, calcium chloride dihydrate, magnesium chloride hexahydrate, water for injections.

What Influvac looks like and contents of the pack

Influvac contains 0.5 ml of a clear, colorless suspension for injection in a glass pre-filled syringe with a stopper (bromobutyl rubber) with or without a needle. Each pre-filled syringe is for single use only.
Pack sizes: 1 or 10 pre-filled syringes.
Not all pack sizes may be marketed.

Marketing authorization holder

Viatris Healthcare Limited
Damastown Industrial Park
Mulhuddart
Dublin 15
DUBLIN
Ireland

Manufacturer

Abbott Biologicals B.V.
Veerweg 12
8121 AA Olst, Netherlands
For more detailed information, please contact the representative of the marketing authorization holder:
Viatris Healthcare Sp. z o.o.
tel. 22 546 64 00

This medicinal product is authorized in the Member States of the European Economic Area and in the United Kingdom (Northern Ireland) under the following names:

Date of last revision of the leaflet:06/2025

The following information is intended for healthcare professionals only:

As with all vaccines given by injection, it should be possible to provide appropriate immediate treatment and medical care in case of an anaphylactic reaction after vaccination.
The vaccine should reach room temperature. Shake before use.
Inspect visually before administration.
Do not use the vaccine if it has changed color or if there are impurities in the suspension.
Do not mix with other medicinal products in the same syringe.
Do not administer the vaccine directly into blood vessels.
The preferred sites for intramuscular injection are the anterolateral part of the thigh (or deltoid muscle if the muscle mass is sufficient) in children from 6 months to 35 months of age, or the deltoid muscle in children from 36 months of age and in adults.
Identifiability
To improve the identifiability of biological medicinal products, the name and batch number of the administered product should be clearly recorded.
See also section 3: How to use Influvac.