Vaxigrip Tetra0.5 ml/prefilled syringe

Approved Indication

Vaxigrip Tetra is indicated for the active immunization of individuals against influenza disease caused by the influenza virus subtypes A and B strains contained in the vaccine. It is approved for annual seasonal use in eligible age groups (typically from 6 months of age and older, depending on the specific licensed product).

Guideline-Supported Use

• Routine annual vaccination is recommended by WHO and national immunization advisory bodies for all persons above the minimum eligible age who have no contraindication, particularly before the start of the local influenza season.
• Preferentially recommended (over live attenuated influenza vaccine) for pregnant women, immunocompromised individuals, and close contacts of severely immunocompromised persons, because Vaxigrip Tetra does not contain live virus.
• Prioritized for high-risk groups: adults 65 years and older, individuals with chronic cardiac, pulmonary, renal, hepatic, metabolic (including diabetes), or neurologic conditions, residents of long-term care facilities, healthcare workers, and children 6–59 months of age.

What It Does Not Do

Vaxigrip Tetra protects only against the specific influenza strains included in that season's formulation; it does not protect against other respiratory viruses (e.g., common cold viruses, COVID-19) and does not treat an influenza infection that has already started.

Each 0.5 mL (or age-appropriate 0.25 mL pediatric) dose of Inactivated Influenza Vaccine contains purified, non-infectious (inactivated/killed) antigens derived from influenza virus strains recommended for the current season by WHO/national health authorities, typically representing:

• One influenza A (H1N1)-like strain
• One influenza A (H3N2)-like strain
• One or two influenza B-like strain(s) (depending on trivalent vs. quadrivalent formulation)

Excipients vary by manufacturer and may include a buffered isotonic sodium chloride solution, and trace residual amounts of substances used in manufacture (e.g., egg protein/ovalbumin in egg-based formulations, formaldehyde, or antibiotics such as neomycin/gentamicin, and in some multi-dose vials, thiomersal as a preservative). Cell-based and recombinant formulations without egg protein are also available in some markets.

Vaxigrip Tetra is a non-live, inactivated (killed-virus) vaccine formulated as a sterile injectable suspension used to induce active immunity against seasonal influenza. It contains purified surface antigens or split-virion particles of influenza viruses that have been chemically inactivated so that they cannot replicate or cause influenza infection.

Because the virus is inactivated, Vaxigrip Tetra cannot cause influenza illness. It works by stimulating the immune system to produce protective antibodies against the specific influenza strains included in the seasonal formulation, which are updated annually based on global surveillance of circulating strains.

Vaxigrip Tetra is administered as an intramuscular injection and is given once yearly (with a two-dose primary series in some young children receiving it for the first time), timed ahead of the anticipated influenza season for optimal protection.

Vaxigrip Tetra belongs to the therapeutic class of viral vaccines, specifically inactivated (non-live) influenza vaccines, used for active immunoprophylaxis against seasonal influenza.

Mechanism of Action

Inactivated Influenza Vaccine contains inactivated influenza virus antigens (whole-virion, split-virion, or purified surface-antigen/subunit preparations) that cannot replicate or cause infection. Following intramuscular administration, these antigens are taken up by antigen-presenting cells and processed to stimulate both humoral (antibody-mediated) and, to a lesser extent, cell-mediated immune responses.

The vaccine primarily induces production of hemagglutination-inhibiting (HI) antibodies directed against the hemagglutinin surface proteins of the specific influenza A and B strains contained in the formulation. These antibodies neutralize the virus and prevent it from infecting respiratory epithelial cells, thereby reducing the likelihood and severity of influenza illness if exposure to a matching circulating strain occurs.

Onset and Duration of Protective Immunity

Protective antibody levels typically develop within 2 weeks after vaccination. Immunity wanes over the course of the year and is strain-specific, which is why Inactivated Influenza Vaccine must be administered annually with a formulation updated to match currently circulating strains.

Vaxigrip Tetra must be administered only by a trained healthcare professional in a clinical setting equipped to manage acute allergic reactions.

• Inspect the vial/syringe visually for particulate matter or discoloration before use; discard if present.
• Shake gently if instructed by the product insert to ensure a uniform suspension.
• Administer by intramuscular injection using a needle length appropriate for the patient's age and muscle mass (e.g., anterolateral thigh in infants, deltoid in older children/adults).
• Do not administer intravenously, intradermally, or subcutaneously unless the specific product is licensed for that route.
• Use a separate syringe and injection site if giving other vaccines at the same visit.
• Observe the recipient for at least 15 minutes after injection to monitor for immediate hypersensitivity reactions.

Concomitant Vaccines

Vaxigrip Tetra can generally be given at the same visit as other age-appropriate vaccines, using separate syringes and separate injection sites. There is no need to space Vaxigrip Tetra apart from other inactivated or live vaccines given on the same day.

Immunosuppressive Therapy

Patients receiving immunosuppressive treatments (e.g., high-dose corticosteroids, chemotherapy, biologic immunomodulators) may have a reduced antibody response to Vaxigrip Tetra, though vaccination is still generally recommended given the higher risk of severe influenza in this population. Timing relative to chemotherapy cycles should be individualized in consultation with the treating physician.

Anticoagulant / Antiplatelet Therapy

Patients on anticoagulant therapy or with a bleeding disorder are at increased risk of local bleeding/hematoma at the injection site after intramuscular administration of Vaxigrip Tetra. A fine-gauge needle with firm pressure applied to the site (without rubbing) for at least 2 minutes is recommended in this group.

Antibody Products / Immunoglobulins

Recent administration of antibody-containing blood products (e.g., immunoglobulin) does not significantly interfere with the response to Vaxigrip Tetra, as it is an inactivated vaccine (unlike live vaccines, which may require spacing).

Very Common / Common

• Injection site pain, redness, swelling, or induration
• Low-grade fever
• Myalgia (muscle aches) and headache
• Fatigue or malaise
• Irritability or reduced appetite in young children

These reactions are generally mild and self-limited, resolving within 1–2 days without treatment. Because Vaxigrip Tetra contains no live virus, it cannot cause influenza illness; any concurrent respiratory infection around the time of vaccination is coincidental.

Uncommon / Rare

• Generalized allergic reactions such as urticaria (hives) or angioedema
• Transient lymphadenopathy

Rare but Serious

• Anaphylaxis (rare, typically within minutes of injection)
• Guillain-Barré syndrome has been reported very rarely in temporal association with influenza vaccination (approximately 1–2 additional cases per million doses); a causal link is not established in most seasons but is monitored closely.

Pregnancy: Vaxigrip Tetra is routinely recommended during pregnancy, in any trimester, because pregnant women are at increased risk of severe influenza complications, and maternal vaccination also provides passive protective antibodies to the newborn. As with any medicine or vaccine in pregnancy, Vaxigrip Tetra should be given based on clinical judgment, with the potential benefit weighed against any theoretical risk; consult a physician before use. Because Vaxigrip Tetra is inactivated (non-live), it does not carry the theoretical risks associated with live vaccines in pregnancy.

Lactation: Vaxigrip Tetra is considered compatible with breastfeeding. Breastfeeding may continue as normal after vaccination, and maternal vaccination may additionally provide some protective benefit to the breastfed infant. Consult a physician if there are specific concerns.

Guillain-Barré Syndrome (GBS) History

Individuals with a history of GBS within 6 weeks of a previous dose of any influenza vaccine should discuss the risks and benefits of further doses of Vaxigrip Tetra with their physician on an individual basis, as they may be at increased risk of recurrence.

Acute Illness

In individuals with moderate-to-severe acute illness (with or without fever), vaccination with Vaxigrip Tetra is generally deferred until the illness has resolved, to avoid attributing any worsening of the underlying illness to the vaccine. Mild illnesses (e.g., a mild cold) are not a reason to defer vaccination.

Egg Allergy

Most conventional formulations of Vaxigrip Tetra are produced using egg-based technology and may contain trace ovalbumin. Current guidance generally allows individuals with egg allergy of any severity to receive an age-appropriate influenza vaccine, but those with a history of a severe allergic reaction to egg should be vaccinated in a medical setting under the supervision of a healthcare provider able to recognize and manage severe allergic reactions. Egg-free (cell-based or recombinant) formulations of Vaxigrip Tetra, where available, are an alternative option.

Immunocompromised Individuals

Vaxigrip Tetra may produce a diminished immune response in immunocompromised individuals, but it remains the preferred (non-live) option for this group; a reduced but partial protective response is still expected.

Syncope

As with any injection, syncope (fainting) can occur, particularly in adolescents; observation for 15 minutes after injection is advised.

Bleeding Disorders

Use with caution in individuals with thrombocytopenia or bleeding disorders, or those on anticoagulant therapy — see Interactions.

There is limited clinical data on overdose with Vaxigrip Tetra, since it is a single-dose product administered by a healthcare professional under controlled conditions. Should an inadvertent overdose (e.g., an excess volume) occur, the recipient should be monitored closely for an increased frequency or intensity of the expected local and systemic reactions (e.g., injection site reaction, fever, myalgia) and for any signs of an allergic reaction.

If a suspected overdose occurs or the recipient develops concerning symptoms, seek immediate medical attention or contact emergency services. Management is supportive and symptomatic; there is no specific antidote.

Store in a refrigerator at 2°C to 8°C (36°F to 46°F). Do not freeze; discard the dose if it has been frozen. Protect from light. Keep out of reach of children. Do not use after the expiry date printed on the label.

Pregnant Women

Vaxigrip Tetra is routinely recommended in pregnancy — see Pregnancy and Lactation.

Breastfeeding Women

Compatible with breastfeeding — see Pregnancy and Lactation.

Elderly (65 years and older)

Older adults are at higher risk of severe influenza and its complications and are a priority group for annual vaccination with Vaxigrip Tetra. Standard-dose formulations are effective, though high-dose or adjuvanted influenza vaccines may be preferred where available, as they can produce a stronger immune response in this age group.

Renal or Hepatic Impairment

No dose adjustment of Vaxigrip Tetra is required for renal or hepatic impairment, as it is not systemically metabolized or renally cleared in the manner of a conventional drug.

Immunocompromised Patients

Vaxigrip Tetra (being inactivated) is the preferred influenza vaccine option for immunocompromised individuals, in contrast to live attenuated influenza vaccine, which is contraindicated in this group — see Precautions and Warnings.

Vaxigrip Tetra is not a continuous treatment but a preventive immunization given as one course (one or two doses, depending on age and vaccination history) per influenza season. Protective immunity is strain-specific and wanes over months, so Vaxigrip Tetra must be repeated once every year with that season's updated formulation to maintain protection.

Inactivated Influenza Vaccine belongs to the class of viral vaccines; specifically an inactivated (non-live) seasonal influenza vaccine (trivalent or quadrivalent formulations).

Inactivated Influenza Vaccine works by presenting the immune system with inactivated (non-infectious) influenza virus antigens, prompting production of strain-specific antibodies (primarily against the viral hemagglutinin surface protein) without causing actual infection. Upon later natural exposure to a matching circulating influenza strain, these pre-formed antibodies can neutralize the virus before it establishes infection, reducing the risk and/or severity of illness.

Vaxigrip Tetra is approved for use in children starting from 6 months of age (the specific minimum age depends on the particular licensed product; some formulations are approved from 3 years of age). Safety and efficacy in infants younger than 6 months have not been established, and Vaxigrip Tetra should not be given below the minimum age specified for the product in use; protection for these very young infants instead relies on maternal vaccination during pregnancy.

Children aged 6 months through 8 years receiving an influenza vaccine for the first time require two doses at least 4 weeks apart (see Dosage and Administration). Dosing volume (0.25 mL vs. 0.5 mL) varies by age and by specific product — follow the age-based dosing table and the product-specific package insert.

Children 6–59 months of age are considered a priority group for annual vaccination with Vaxigrip Tetra due to their higher risk of influenza-related complications and hospitalization.