hepatitis A vaccine, inactivated
Havrix, Vaqta

Available forms
Available by prescription only
Injection: 720 EL units/0.5 ml, 1,440 EL units/1 ml (Havrix); 25 units/0.5 ml, 50 units/0.5 ml (Vaqta)

Indications and dosages
 Immunization against disease caused by hepatitis A virus. Adults: 1,440 ELISA units (EL units)/1 ml (Havrix) I.M. as a single dose. Give booster dose of 1,440 EL units/1 ml I.M. 6 to 12 months after initial dose. Or 50 units (Vaqta) I.M. and booster dose 6 months after initial dose.
Children ages 2 to 18: 720 EL units/1 ml (Havrix) I.M. as a single dose and booster dose 6 to 12 months after initial dose.
Children ages 2 to 17: Single dose of 25 units (Vaqta) I.M. and booster dose 6 to 18 months after initial dose.

Pharmacodynamics
Immunostimulant action: Hepatitis A vaccine, inactivated, promotes active immunity to hepatitis A virus. Immunity isn’t permanent or completely predictable.

Pharmacokinetics
Absorption: No information available.

Contraindications and precautions
Contraindicated in patients hypersensitive to any component of vaccine. Use cautiously in patients with thrombocytopenia or bleeding disorders and in those taking anticoagulants; bleeding may occur after I.M. injection.

Interactions
None significant.

Adverse reactions
CNS: malaise, fatigue, headache, insomnia, vertigo, fever.
EENT: pharyngitis, photophobia.
GI: anorexia, nausea, abdominal pain, diarrhea, dysgeusia, vomiting.
Hepatic: jaundice, hepatitis.
Musculoskeletal: arthralgia, myalgia.
Respiratory: upper respiratory tract infections.
Skin: pruritus, rash, urticaria, induration, redness, swelling at injection site, hematoma.
Other: lymphadenopathy, hypertonic episode.

Effects on lab test results
• May increase CK level.

Overdose and treatment
No information available.

Special considerations
• As with any vaccine, administration of hepatitis A vaccine should be delayed, if possible, in patients with febrile illness.
• Although anaphylaxis is rare, have epinephrine available to treat this reaction.
• If vaccine is administered to immunosuppressed persons or those receiving immunosuppressive therapy, the expected immune response may not be obtained.
• There are no data to support routine vaccination of individuals with chronic hepatitis B or C who lack evidence of chronic liver disease.
• Persons who should receive the vaccine include people traveling to or living in areas of higher endemicity for hepatitis A (Africa, Asia [except Japan], the Mediterranean basin, Eastern Europe, the Middle East, Central and South America, Mexico, and parts of the Caribbean), military personnel, natives of Alaska and the Americas, persons engaging in high-risk sexual activity, and users of illicit injectable drugs. Also, certain institutional workers, child day-care workers, laboratory workers who handle live hepatitis A virus, and handlers of primate animals may benefit from immunization.
• A positive result in the absence of infection may occur in individuals who received hepatitis A vaccine and who are being evaluated by serology to detect IgM anti-HAV.
• Serologic confirmation of immunity isn’t needed.
Breast-feeding patients
• It isn’t known whether vaccine appears in breast milk. Use cautiously in breast-feeding women.
Pediatric patients
• Vaccine is well tolerated, highly immunogenic, and effective in children age 2 and older.

Patient education
• Inform patient that vaccine won’t prevent hepatitis caused by other agents such as hepatitis B virus, hepatitis C virus, hepatitis E virus, or other pathogens known to infect the liver.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use