Influvac (Influenza Virus B/Austria/1359417/2021-Like Strain (B/Austria/1359417/2021, Bvr-26), Influenza A/Vic)

Influvac is a vaccine that targets the influenza virus family to provide prophylactic protection against seasonal flu.

• Seasonal influenza (A): Induces protective antibodies that lower the incidence of influenza A infection.
• Seasonal influenza (B): Generates immunity that reduces the risk of influenza B disease.
• General seasonal influenza: Decreases overall flu‑related illness severity and complications across all age groups.

• Influvac contains inactivated influenza virus antigens that stimulate the host immune system to produce specific antibodies against hemagglutinin and neuraminidase proteins. These antibodies neutralize the virus and prevent its attachment to respiratory epithelial cells, thereby providing active immunity against subsequent exposure to the matched influenza strains.

Common Side Effects

• Injection site pain: Mild to moderate discomfort at the injection site.
• Redness or swelling: Localized erythema or edema around the injection area.
• Low‑grade fever: Transient temperature rise within 24‑48 hours.
• Headache: Mild headache occurring shortly after vaccination.
• Myalgia: Muscle aches that resolve within a few days.

Serious or Rare Side Effects

• Anaphylaxis: Severe allergic reaction requiring immediate medical attention.
• Guillain‑Barré syndrome: Rare neurological disorder potentially linked to vaccination.
• Seizures: Uncommon febrile seizures in susceptible individuals.
• High fever: Persistent temperature above 39°C lasting more than 48 hours.
• Severe allergic reaction: Angioedema or bronchospasm requiring emergency care.

Influvac should be administered with consideration of the following precautions.

• Allergy screening: Avoid use in persons with known hypersensitivity to any vaccine component.
• Acute illness: Postpone vaccination in individuals with moderate or severe febrile illness.
• Pregnancy: Consult a healthcare professional; limited safety data are available.
• Immunocompromised patients: May exhibit reduced immunogenic response; monitor effectiveness.
• Age restriction: Not recommended for children younger than six months.
• Store at 2-8°C: Keep refrigerated, protect from light, do not freeze or shake the vial.

Vaccination with Influvac may be influenced by other medical products.

Major Interactions (Avoid)

• Live attenuated vaccines: Do not co‑administer within four weeks to prevent interference.
• Immunoglobulins or blood products: May diminish vaccine‑induced immunity if given concurrently.

Moderate Interactions (Monitor Closely)

• Antipyretics (e.g., acetaminophen): May mask post‑vaccination fever.
• Immunosuppressive therapy: Could reduce antibody response; assess timing.
• Other inactivated vaccines: Generally safe together but monitor for additive local reactions.