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

Influvac Tetra is an influenza vaccine that works within the respiratory viral infection pathway to prevent seasonal flu.

• Seasonal influenza: provides prophylactic protection against infection caused by the influenza virus strains included in the vaccine.
• Children (6 months–17 years): reduces the risk of influenza illness and related complications in pediatric populations.
• Elderly (65 years and older): lowers the likelihood of severe influenza outcomes and hospitalization in older adults.

• Influvac Tetra contains inactivated viral antigens from the specified influenza B strains. After intramuscular injection, the antigens are taken up by antigen‑presenting cells, stimulating a humoral immune response that generates strain‑specific antibodies against hemagglutinin and neuraminidase proteins. The vaccine also activates helper T‑cells, enhancing the overall adaptive immune response and contributing to longer‑lasting protection.

Influvac Tetra may cause local and systemic reactions, most of which are mild and transient.

Common Side Effects

• Injection site pain: mild soreness at the injection site lasting 1–2 days.
• Redness or swelling: localized erythema or edema that resolves within a few days.
• Low‑grade fever: temperature rise up to 38 °C occurring within 24 hours.
• Headache or muscle aches: transient discomfort reported after vaccination.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction requiring immediate medical attention.
• Guillain‑Barré syndrome: rare neurological disorder that may develop weeks after vaccination.
• Seizures: uncommon febrile convulsions, particularly in young children.

When using Influvac Tetra, certain precautions should be observed to ensure safety and optimal effectiveness.

• Pregnancy: consult a healthcare professional before vaccination, as safety data are limited.
• Egg allergy: avoid if the patient has a severe allergy to egg proteins or vaccine constituents.
• Age restriction: not indicated for children younger than 6 months of age.
• Immunocompromised individuals: vaccine may elicit a reduced immune response; monitor closely.
• Fever monitoring: observe for high fever or systemic reactions following administration.
• Store at 2‑8 °C: keep refrigerated, protect from light, do not freeze or shake the vial.

Influvac Tetra may interact with certain medical products; awareness of these interactions helps maintain vaccine efficacy.

Major Interactions (Avoid)

• Live attenuated influenza vaccine: avoid co‑administration within 4 weeks to prevent interference.
• Immunoglobulin or blood products: avoid within 3 months as they may neutralize vaccine antigens.
• Antiviral medications: concurrent use may diminish antibody response.

Moderate Interactions (Monitor Closely)

• Antipyretic agents (e.g., acetaminophen) taken prophylactically: may slightly reduce immunogenicity.
• Immunosuppressive therapy: may lower vaccine effectiveness, requiring assessment.
• Seasonal antiviral prophylaxis: monitor for potential reduced vaccine benefit.