Havrix (Hepatitis A Virus (Inactivated), Algeldrate)

Havrix is indicated for the prevention of hepatitis A infection in individuals who have not been previously immunized or who require booster protection.

• Primary prophylaxis for adults and children aged 12 months and older who are at risk of hepatitis A exposure.
• Pre‑travel vaccination for persons traveling to regions where hepatitis A is endemic.
• Post‑exposure prophylaxis for close contacts of confirmed hepatitis A cases when vaccine is administered within two weeks of exposure.
• Booster dosing for individuals who received a complete hepatitis A vaccine series at least 15 years earlier.
• Immunization of individuals with chronic liver disease to reduce the risk of severe hepatitis A complications.

The safety profile of Havrix reflects the typical reactions observed with inactivated viral vaccines, most of which are mild and transient and usually resolve without intervention.

Common

• Pain, redness, or swelling at the injection site.
• Low‑grade fever.
• Headache or mild fatigue.
• Nausea or transient gastrointestinal discomfort.
• Mild muscle aches at or near the injection site.
• Transient rash elsewhere on the body.
• Mild fever lasting less than 24 hours.

Serious

• Severe allergic reaction (anaphylaxis) characterized by difficulty breathing, swelling of the face or throat, and rapid heartbeat.
• Neurologic events such as Guillain‑Barré syndrome, although these are rare.
• Severe thrombocytopenia presenting with easy bruising or bleeding.

Precautions for Havrix focus on patient history, immune status, and proper administration techniques to ensure safety and effectiveness.

• Verify that the individual has no known severe allergy to any vaccine component, including algeldrate.
• Defer vaccination in persons with acute moderate or severe illness until recovery.
• Assess immune competence; immunocompromised patients may have a reduced antibody response.
• Avoid intramuscular injection into the buttock; use the deltoid or anterolateral thigh for appropriate age groups.
• Observe the patient for at least 15 minutes after injection to monitor for immediate allergic reactions.
• Store the vaccine according to the manufacturer’s instructions, typically refrigerated between 2 °C and 8 °C, and protect from freezing.

Havrix does not have many documented drug‑drug interactions, but certain substances and conditions may influence its administration or immune response.

Avoid

• Live viral vaccines administered within four weeks before or after Havrix should be avoided to prevent potential interference with immune response.
• Immunoglobulin or blood products given within two weeks of vaccination may reduce the effectiveness of the hepatitis A vaccine.

Use with caution

• Antipyretics such as acetaminophen or ibuprofen may be used to manage mild post‑vaccination symptoms, but routine prophylactic use before vaccination is not recommended.
• Patients receiving immunosuppressive therapy (e.g., corticosteroids, biologics) may have a diminished antibody response and should be evaluated for adequate protection.
• Pregnant or breastfeeding individuals should discuss vaccination with their healthcare provider, as safety data are limited.