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

Influsplit is a split‑virion influenza vaccine used to prevent infection by influenza A and B viruses.

• Seasonal influenza (influenza A and B): provides active immunization to reduce the risk of infection and related complications.
• High‑risk groups (elderly, chronic disease patients): lowers incidence of flu‑associated hospitalization and severe outcomes.
• Healthcare personnel: decreases transmission potential in clinical environments and protects vulnerable patients.

• Influsplit contains purified split virion antigens from selected influenza A (Victoria lineage) and influenza B (Austria lineage) strains. After intramuscular injection, the viral hemagglutinin and neuraminidase proteins are taken up by antigen‑presenting cells, triggering a humoral immune response that generates strain‑specific neutralizing antibodies and cellular immunity, thereby establishing active protection against subsequent exposure to the matched influenza viruses.

Influsplit may be associated with local and systemic reactions following injection.

Common Side Effects

• Injection site pain: mild to moderate discomfort at the injection site.
• Redness or swelling: localized erythema or edema.
• Low‑grade fever: transient temperature rise within 24 hours.
• Headache: mild headache occurring shortly after vaccination.
• Myalgia: temporary muscle aches.

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: infrequent convulsive episodes, especially in febrile children.

Before administering Influsplit, consider the following precautions to ensure safe use.

• Allergy assessment: avoid vaccination in individuals with a history of severe allergic reaction to any component of the vaccine.
• Acute illness: defer vaccination in persons with moderate or severe febrile illness until recovery.
• Post‑vaccination observation: monitor recipients for at least 15‑30 minutes for signs of anaphylaxis.
• Immunocompromised status: consult a specialist before vaccinating patients with severe immunosuppression, as response may be reduced.
• Store at 2‑8 °C: keep refrigerated, protect from light, do not freeze or shake.

Influsplit can interact with other medical products; relevant interactions are listed below.

Major Interactions (Avoid)

• Live viral vaccines: avoid co‑administration within 4 weeks as interference may reduce efficacy.
• Immunoglobulin or blood products: concurrent use may diminish antibody response to the vaccine.

Moderate Interactions (Monitor Closely)

• Antiviral agents (e.g., oseltamivir): may slightly affect immune response; schedule vaccination before initiating therapy when possible.
• Immunosuppressive therapy: may lower vaccine‑induced immunity; monitor antibody titers if clinically indicated.
• Fever‑reducing medications: antipyretics taken prophylactically can mask mild post‑vaccination symptoms.