Havrix (Algeldrate, Hepatitis A Virus Antigen (Inactivated))

Havrix is an injectable hepatitis A vaccine containing 720 ELU/0.5 mL of algeldrate combined with inactivated hepatitis A virus antigen, supplied as a sterile solution for intramuscular administration. It is marketed in the European Union as a prescription‑only product and belongs to the vaccine class used for active immunization against hepatitis A infection. The formulation is designed to stimulate protective antibody production in healthy individuals and those at risk.

Havrix is indicated for the prevention of hepatitis A virus infection in individuals who are at risk of exposure or who seek immunization.

- Primary prophylaxis for hepatitis A in adults and children aged 12 months and older. - Pre‑travel vaccination for persons traveling to regions with intermediate or high hepatitis A endemicity. - Immunization of laboratory personnel handling hepatitis A specimens. - Protection of individuals with chronic liver disease or clotting‑factor disorders. - Use in outbreak settings to quickly establish herd immunity.

Following intramuscular injection, Havrix may cause transient reactions at the injection site and systemic symptoms that are generally mild and self‑limiting.

Common: - Pain, redness, or swelling at the injection site. - Low‑grade fever (≤38 °C) within 24 hours. - Headache or mild fatigue. - Nausea or mild gastrointestinal discomfort. - Muscle aches or joint pain. - Transient swelling of lymph nodes near injection site. - Temporary dizziness or feeling of light‑headedness.

Serious: - Severe allergic reaction (anaphylaxis) with difficulty breathing, hives, or swelling of the face. - Guillain‑Barré syndrome reported rarely after vaccination. - Persistent high fever or neurologic symptoms requiring medical evaluation. - Seizures or loss of consciousness (very rare).

Healthcare providers should assess individual health status before administering Havrix and observe recommended safety measures to minimize risk.

- Defer vaccination in persons with known severe allergic reaction to any component of the product. - Postpone administration in individuals experiencing acute moderate or severe illness until recovery. - Use with caution in pregnant or breastfeeding women; benefits should outweigh potential risks. - Monitor for signs of anaphylaxis for at least 15 minutes after injection. - Consider alternative hepatitis A prophylaxis for immunocompromised patients with impaired antibody response. - Do not administer intravascularly; ensure proper intramuscular technique. - Record batch number and expiration date for traceability.

Havrix does not contain pharmacologically active drugs, but certain substances may affect vaccine response or safety.

Avoid: - Concomitant administration of other live vaccines (e.g., measles, mumps, rubella) at the same anatomical site. - Use of immunoglobulin products within 2 weeks before or after vaccination, which may reduce immunogenicity. - Simultaneous receipt of blood products that could interfere with antibody formation.

Use with caution: - Immunosuppressive therapies (e.g., corticosteroids, chemotherapy) that may diminish antibody response. - Antipyretic or analgesic medications (e.g., acetaminophen, ibuprofen) taken prophylactically, which could mask mild systemic reactions. - Chronic alcohol consumption, which may impair immune function.