Havrix

Havrix is an injectable vaccine containing inactivated hepatitis A virus (1440 ELU per 0.5 mL) and algeldrate as a stabilizer. It is supplied as a sterile solution for intramuscular administration and is marketed in the European Union for the prevention of hepatitis A infection.

Havrix is indicated for active immunisation against hepatitis A virus. It is used in the following situations:

- Routine vaccination of children and adults in endemic areas - Pre‑travel protection for persons visiting regions with high hepatitis A prevalence - Post‑exposure prophylaxis when administered within two weeks of exposure - Vaccination of individuals with chronic liver disease to reduce severe outcomes - Immunisation of laboratory personnel handling hepatitis A specimens

Most recipients experience mild, transient reactions after Havrix injection. Serious adverse events are rare.

Common: - Injection‑site pain or redness - Low‑grade fever - Headache - Fatigue or malaise - Muscle aches - Nausea

Serious: - Severe allergic reaction (anaphylaxis) - Guillain‑Barré syndrome (very rare) - High fever persisting >48 hours - Persistent joint swelling - Neurological symptoms such as weakness or numbness

Before receiving Havrix, consider the following precautions:

- Verify no severe allergy to any vaccine component, especially gelatin or latex. - Defer vaccination in individuals with moderate or severe acute illness. - Discuss vaccination with pregnant or breastfeeding persons; safety data are limited. - Assess immune status; immunocompromised patients may have reduced antibody response. - Review history of Guillain‑Barré syndrome, as recurrence is possible. - Ensure proper storage and handling to maintain vaccine potency.

Havrix generally has a low potential for drug interactions, but consider these situations:

Avoid: - Concurrent administration of live vaccines within 4 weeks, as immune response may be affected. - Use with systemic corticosteroids at immunosuppressive doses, which can diminish antibody production.

Use with caution: - Antipyretics (e.g., acetaminophen, ibuprofen) may mask low‑grade fever after vaccination. - Immunoglobulin therapy given within 2 weeks before or after vaccination can interfere with immune response. - Blood products or plasma containing anti‑hepatitis A antibodies may reduce vaccine efficacy.