Havrix

Havrix is a hepatitis A vaccine containing inactivated hepatitis A virus adsorbed on aluminium hydroxide, supplied as an injectable solution. The product is authorized in the European Union and is prescribed for active immunization against hepatitis A infection. It is administered intramuscularly by a healthcare professional. The formulation does not include a listed strength, as dosing is based on volume per vial for each patient receiving the vaccine.

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

- Adults and children aged 12 months and older who have not been previously immunized. - Pre‑travel protection for persons traveling to regions where hepatitis A is endemic. - Post‑exposure prophylaxis for individuals who have been in close contact with a confirmed case of hepatitis A. - Use in outbreak settings to rapidly increase community immunity. - Immunization of healthcare workers who may be exposed to hepatitis A through patient care. - Vaccination of individuals with chronic liver disease to reduce the risk of severe hepatitis A complications.

Following intramuscular administration, Havrix may be associated with a range of adverse reactions, most of which are mild and transient. These events typically resolve without medical intervention within a few days. Most individuals experience no more than mild discomfort after vaccination.

Common: - Injection site pain, redness or swelling. - Low‑grade fever or mild headache. - Fatigue or general feeling of being unwell. - Transient joint or muscle aches. - Mild nausea or gastrointestinal discomfort.

Serious: - Severe allergic reaction (anaphylaxis) characterized by difficulty breathing, swelling of the face or throat, or hives. - Guillain‑Barré syndrome, a rare neurological condition causing muscle weakness. - Persistent high fever or seizures (very rare).

Healthcare providers should evaluate individual risk factors and medical history before administering Havrix to ensure safe immunization.

- Defer vaccination in persons with known severe allergy to any vaccine component, especially aluminium salts. - Postpone administration in individuals experiencing acute moderate or severe illness until recovery. - Use with caution in patients with immunocompromised conditions, as response may be reduced. - Consider delaying vaccination in pregnant women; safety data are limited. - Monitor for anaphylactic reactions for at least 15 minutes after injection. - Assess liver disease status, as hepatitis A infection can be more severe in chronic liver disease. - Review prior hepatitis A vaccination history to avoid unnecessary repeat dosing.

Havrix generally has a low potential for drug interactions, but certain concomitant therapies may require attention.

Avoid: - Avoid administration with immunoglobulin products within 2 weeks, as they may reduce vaccine efficacy. - Avoid use of systemic corticosteroids at high doses during vaccination, as they may impair immune response.

Use with caution: - Use with caution in patients receiving immunosuppressive therapy, including biologics, because response may be diminished. - Use with caution when co-administered with other vaccines; monitor for increased reactogenicity. - Use with caution in individuals on antipyretics; they may mask fever. - Use with caution in patients receiving blood products, as they may interfere with antibody formation.