Influvac Tetra (B/Phuket/3073/2013-Like Virus (B/Phuket/3073/2013, Wild Type), Influenza Virus B/Austria/1359417/202)

• Influvac Tetra is a quadrivalent influenza vaccine used to prevent seasonal influenza caused by specific B virus strains.
• Seasonal influenza (B/Phuket/3073/2013-like strain): Provides protective immunity to reduce the risk of infection with this circulating B virus.
• Seasonal influenza (B/Austria/1359417/202 strain): Induces antibody response that lowers the incidence of illness caused by this B virus.
• Children aged 6 months and older: Helps decrease laboratory‑confirmed influenza cases in pediatric populations.

• The vaccine contains inactivated influenza B virus antigens from the B/Phuket/3073/2013-like and B/Austria/1359417/202 strains. After intramuscular or subcutaneous injection, these antigens are taken up by antigen‑presenting cells, which process and display them to T‑lymphocytes. This activates B‑cells to produce strain‑specific neutralizing antibodies, establishing humoral immunity that can rapidly neutralize the corresponding influenza viruses upon exposure and contributes to immunological memory for future protection.

Common and serious adverse reactions may occur after administration of Influvac Tetra.

Common Side Effects

• Injection site pain: mild to moderate discomfort at the injection site.
• Redness: localized erythema around the injection area.
• Swelling: temporary edema at the site of administration.
• Fever: low‑grade temperature rise within 24‑48 hours.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction requiring immediate medical attention.
• Guillain‑Barré syndrome: rare neurological disorder that may develop after vaccination.

• Precautions should be observed before administering Influvac Tetra.
• Allergy assessment: verify no previous severe reaction to influenza vaccines or any component.
• Pregnancy and lactation: consult healthcare provider; vaccine may be administered if benefits outweigh potential risks.
• Immunocompromised patients: vaccine may be less immunogenic; timing should be coordinated with treating physician.
• Age eligibility: approved for individuals aged 6 months and older.
• Concurrent medications: no specific contraindication, but inform provider of immunoglobulins or steroids.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Potential drug interactions should be considered when planning vaccination.

Major Interactions (Avoid)

• Live attenuated vaccines: avoid simultaneous administration; separate by at least 4 weeks.
• Immunoglobulin therapy: avoid within 2 weeks before or after vaccination.

Moderate Interactions (Monitor Closely)

• Antipyretic medications (acetaminophen, ibuprofen): prophylactic use may diminish antibody response; monitor.
• Immunosuppressive drugs (e.g., corticosteroids, chemotherapy): may reduce vaccine efficacy; monitor.
• Antihistamines: may mask mild allergic reactions; monitor.