Havrix

Havrix is an injectable hepatitis A vaccine containing inactivated hepatitis A virus adsorbed on aluminium hydroxide, produced on human diploid cells. It is supplied in a sterile liquid form for intramuscular administration and is marketed in the European Union. The product is prescription‑only and is classified as a prophylactic vaccine (ATC code J07BB01) that stimulates protective antibodies against hepatitis A virus and provides long‑term immunity.

Havrix is indicated for the prevention of hepatitis A virus infection in individuals at risk.

- Healthy adults and children aged 12 months and older who require protection against hepatitis A. - Travelers to regions where hepatitis A is endemic or where outbreaks have occurred. - Persons with occupational exposure to hepatitis A, such as laboratory workers handling the virus. - Individuals with chronic liver disease who need additional protection. - Close contacts of patients with confirmed hepatitis A infection.

The safety profile of Havrix includes both common, generally mild reactions and rare, serious events.

Common: - Pain, redness, or swelling at the injection site. - Low‑grade fever. - Headache. - Fatigue or malaise. - Muscle aches.

Serious: - Severe allergic reaction (anaphylaxis) with difficulty breathing or swelling of the face. - Guillain‑Barré syndrome (rare neurological condition). - Thrombocytopenia (low platelet count). - Seizures (rare).

Before administering Havrix, healthcare providers should consider several precautionary factors.

- Known severe allergy to any component of the vaccine, including aluminium hydroxide. - History of anaphylaxis after a previous dose of Havrix or another hepatitis A vaccine. - Acute moderate or severe illness; vaccination should be postponed until recovery. - Pregnancy and breastfeeding status should be discussed with a clinician, as data are limited. - Immunocompromised individuals may have a reduced antibody response and may require additional dosing. - Children under 12 months are not approved for this vaccine.

Havrix may interact with other medical products, influencing safety or immune response.

Avoid: - Concurrent administration with other live vaccines (e.g., measles, mumps, rubella) without appropriate interval. - Use of immunoglobulin products that may neutralize the vaccine antigen if given shortly before or after vaccination.

Use with caution: - Simultaneous receipt of other inactivated vaccines (e.g., influenza) – generally acceptable but monitor for increased local reactions. - Patients receiving immunosuppressive therapy may have diminished vaccine efficacy. - Antipyretic or analgesic medications (e.g., acetaminophen) taken prophylactically may mask mild systemic reactions.