Hepatitis A Vaccine (Havrix) is an inactivated vaccine that is administered intramuscularly. It is used to prevent hepatitis A virus disease especially in high-risk patients such as those with pre-existing liver disease.

Hepatitis A Vaccine (Havrix) Uses:

• Hepatitis A virus disease prevention:

  • It is intended for use in the active vaccination of people aged 1 and older against hepatitis A virus illness (HAV).

  • The Advisory Committee on Immunization Practices (ACIP) recommends routine vaccination for:

    • All children ≥1 year of age
    • All unvaccinated adults requesting protection from HAV infection
    • Unvaccinated persons with any of the following conditions:
      • Injection and non-injection illicit drug users 
      • Men who have sex with men
      • people with chronic liver disease
      • patients receiving clotting-factor concentrates 
      • people travelling to or working in countries with high or intermediate levels of endemic HAV infection,
      • people under the age of one who are homeless 
      • people who work with HAV-infected primates
      • people who work with HAV in a research laboratory setting.
    • Unvaccinated individuals who may come into touch closely with an international adoptee from a countries with a moderate to high HAV endemicity during the first 60 days after their arrival in the United States (eg, household contacts, babysitters).
    • According to local public health authorities, vaccination may be used as part of the response to a hepatitis A outbreak or as postexposure prophylaxis for patients under 12 months old within two weeks of exposure.

  • The Canadian National Advisory Committee on Immunization (NACI) also recommends vaccination for the following:

    • those younger than six months who are at risk for contracting hepatitis A or who have severe hepatitis A (eg, underlying hepatic disease of idiopathic, metabolic, infectious, or cholestatic etiology)
    • infants younger than six months who are housed with a person at high risk for hepatitis A infection or severe hepatitis A
    • Postexposure prophylaxis:
      • Healthy individuals 6 months (vaccine is preferred over immune globulin [Ig])
        Adults who are vulnerable and under 60 years old and who live with or are in close proximity to a case within two weeks of exposure (Ig may also be given)
      • Those with chronic liver disease who are at risk (Ig should also be administered within 14 days of exposure)
    • Patients who get repeated plasma-derived clotting factor treatment may want to take this into consideration.

Hepatitis A Vaccine (Havrix) Dose in Adults

Hepatitis A Vaccine (Havrix) for Primary immunization in Adults:

Note:

• The vaccine should be administered at least two weeks before to anticipated hepatitis A virus (HAV) exposure when used as a primary vaccination.
• The immunisation series should start when the adoption is being planned when utilised before an overseas adoption, but ideally 14 days before the adoptee is anticipated to arrive.

• Manufacturer’s labeling:

  • Avaxim [Canadian product]:
    • IM: Following the first vaccination, recipients should receive a booster dose of 160 units (0.5 mL) administered 6 to 36 months later.
  • Havrix:
    • IM: A booster dose of 1,440 ELISA units (1 mL) should be administered 6–12 months following the first vaccination.
  • VAQTA:
    • IM: 50 units (1 mL), followed by a booster dose of 50 units (1 mL), to be administered 6–18 months after the primary immunisation (6–12 months if the first dose).

Hepatitis A Vaccine (Havrix) Postexposure prophylaxis (off-label):

• Adults without immunity:

  • IM: Give a single dose as soon as feasible (within two weeks) after a recent exposure to HAV; for long-term protection, finish the vaccine series with a second dose 6 months after the first dose.

Hepatitis A Vaccine (Havrix) Dose in Children:

Note:

• For more information, including specific, detailed recommendations for catch-up scenarios and/or the management of patients with high-risk diseases, consult the CDC/ACIP yearly immunisation schedules or the National Advisory Committee on Immunization (NACI) guidelines (Canada).
• The ACIP considers dosages given 4 days before the minimum interval or age to be valid; however, local or state regulations may take precedence over this time period.

Hepatitis A Vaccine (Havrix) dose for Primary immunization:

Note:

• The vaccine should be administered at least 14 days before anticipated hepatitis A virus (HAV) exposure when used as a primary vaccination.
• The immunisation series should begin when the adoption is being arranged, but no later than two weeks before the adoptee is anticipated to arrive.

• ACIP recommendations: Havrix, VAQTA:

Note:

• Havrix and VAQTA are regarded as interchangeable for booster doses, despite the fact that it is preferable to use the vaccines in accordance with their approved labelling.
  • Children 12 to 23 months:
    • IM: 0.5 mL per dose for a total of two doses.
    • The first dose should be given between the ages of 12 and 23 months, and the subsequent doses should be spaced out by 6 to 18 months.
  • Children ≥2 years and Adolescents (unvaccinated) if immunity against hepatitis A virus infection is desired:
    • IM: 0.5 mL per dose for a total of two doses separated by 6 to 18 months.

Note:

• The interval between Havrix doses should be 6 to 12 months, while the interval between VAQTA doses should be 6 to 18 months.
• If primary Havrix is followed by a booster dosage of VAQTA, the booster dose should be administered 6 to 12 months after the primary dose.

• Canadian labeling:

Note: Although dose amount is the same, product concentrations and recommended ages vary; carefully read the product label to verify accuracy.

• • Avaxim-Pediatric [Canadian product]:

    • Children and Adolescents ≤15 years:
      • IM: Ideally, the primary vaccination series should be given 6 to 36 months after the first dose, but it is possible to give the booster dose up to 7 years later.
      • Note: Anti-HAV antibodies have been seen up to 14 to 15 years following primary series with Avaxim-Pediatric in healthy participants; the requirement for a second booster dose has not been established.

  • Avaxim [Canadian product]:

    • Children ≥12 years and Adolescents:
      • IM: 0.5 mL followed by a booster dose of 0.5 mL to be administered six to thirty-six months following the initial immunisation.

Hepatitis A Vaccine (Havrix) for Catch-up immunization:

• CDC (ACIP) recommendations:

Note: Avoid starting the series over. If doses have been administered, start the next schedule at the corresponding dose number.

• • Children ≥2 years and Adolescents if immunity against HAV infection is desired:

    • IM: 0.5 mL every dose, split into two doses that are at least six months apart.

Hepatitis A Vaccine (Havrix) for Preexposure prophylaxis:

• Infants 6 to 11 months of age:

  • IM: 0.5 mL once, administer as soon as travel is considered.
  • Note: The full 2-dose primary vaccination regimen for hepatitis A should be begun at 12 months of age; doses do not count toward the primary immunisation series (see Primary Immunization).

Hepatitis A Vaccine (Havrix) for Postexposure prophylaxis:

• Children and Adolescents without immunity:

  • IM: 0.5 mL as quickly as possible after recent HAV exposure (within the previous two weeks); immunocompromised people or people with chronic liver disease should also get immune globulin.
  • Although a second dose of the vaccine is not necessary for postexposure prophylaxis, it should be taken into consideration six months after the first dose to finish the hepatitis A vaccine series and provide long-lasting immunity.

Hepatitis A Vaccine (Havrix) Pregnancy Risk Category: C

• Although the safety of vaccinations during pregnancy is not known, it is believed that there is a low risk for the infant.
• Limited data has not shown that maternal vaccinations during the first and second trimesters of pregnancy increase the risk of miscarriage and major birth defects. 
• The fetus is not at increased risk from inactivated vaccines.

Hepatitis A vaccine that can be used during breastfeeding

• It is unknown if the vaccine is absorbed into breast milk.
• According to the manufacturer's instructions, the decision about whether to continue breastfeeding or stop breastfeeding following an immunization must be based on the risks of infant exposure, the benefits to the infant of breastfeeding, and the benefits to the mother of getting vaccinated.
• Inactivated vaccines are not harmful to infants or mothers.
• Breastfeeding infants must be vaccinated according the recommended schedules.

Dose in Kidney Disease

No dosage adjustment in the manufacturer's labeling.

Hepatitis A Vaccine (Havrix) Dose in Liver disease:

• No dosage adjustment in the manufacturer's labeling.
• In contrast to healthy participants, results indicate that people with chronic liver disease show a reduced antibody response to HAVRIX.

Age, the product being used, and concurrent vaccination administration all affect frequency. In average, younger children experienced fewer headaches and injection site reactions.

Common Side Effects of Hepatitis A Vaccine (Havrix):

• Central Nervous System:

  • Irritability
  • Headache
  • Drowsiness

• Gastrointestinal:

  • Decreased Appetite

• Local:

  • Injection Site Reaction
  • Swelling At Injection Site
  • Pain At Injection Site
  • Tenderness At Injection Site
  • Erythema At Injection Site

• Neuromuscular & Skeletal:

  • Weakness

• Miscellaneous:

  • Fever

Less Common Side Effects Of Hepatitis A Vaccine (Havrix):

• Central Nervous System:

  • Fatigue
  • Malaise
  • Chills
  • Insomnia

• Dermatologic:

  • Skin Rash

• Endocrine & Metabolic:

  • Menstrual Disease

• Gastrointestinal:

  • Anorexia
  • Nausea
  • Constipation
  • Gastroenteritis
  • Vomiting
  • Diarrhea
  • Abdominal Pain

• Local:

  • Induration At Injection Site
  • Bruising At Injection Site

• Neuromuscular & Skeletal:

  • Myalgia
  • Back Pain
  • Stiffness
  • Arm Pain

• Ophthalmic:

  • Conjunctivitis

• Otic:

  • Otitis Media

• Respiratory:

  • Rhinorrhea
  • Cough
  • Nasopharyngitis
  • Pharyngitis
  • Nasal Congestion
  • Rhinitis
  • Upper Respiratory Tract Infection
  • Asthma

• Miscellaneous:

  • Fever ≥102°F
  • Excessive Crying

Contraindications to Hepatitis A Vaccine (Havrix):

immediate and/or severe allergic or hypersensitive reaction to any ingredient in the formulation, including neomycin, or to immunizations that include hepatitis A.

Warnings and precautions

• Anaphylactoid reactions and hypersensitivity reactions

  • During the administration of the vaccine, immediate medical assistance, including epinephrine 1 mg/mL, must be available for anaphylactoid and/or hypersensitive reactions.

• Syncope

  • Syncope can be caused by injectable vaccines. It is most common in young adults and adolescents, and usually occurs within 15 minutes of vaccination.
  • It is important to take precautions to prevent injuries from falling, and to restore cerebral perfusion in the event of syncope.

• Acute illness:

  • The severity of the symptoms and the etiology determine whether or not vaccination should be administered.
  • Vaccines should be administered as soon as feasible to patients with severe or moderate acute illnesses.
  • Patients with modest acute illnesses shouldn't postpone their administration, fever or not.

• Bleeding disorders:

  • Patients with bleeding disorders, including thrombocytopenia, should be cautious about IM administration.
  • IM administration can result in bleeding or hematomas.
  • Injections into the intramuscular cavity (IM) can be arranged within a few hours if the patient is getting anti-hemophilia therapy or another similar therapy.
  • Subcutaneous administration may not always be allowed, according to Canadian product labels (eg patients at high risk of hemorhage or thrombocytopenia).
  • But there might be more of a chance for local reactions (eg injection site nodule).
  • After a subcutaneous injection of VAQTA, seroconversion in healthy persons was slower than after an intramuscular injection.

• Hepatic impairment

  • Those with chronic liver illness are advised; patients with weakened immune systems might not be the best candidates.

Monitoring parameters:

• Liver function tests;
• Monitor for anaphylaxis and syncope for 15 minutes following administration.
• If seizure-like activity associated with syncope occurs, maintain the patient in supine or Trendelenburg position to maintain adequate cerebral perfusion.

How to administer Hepatitis A Vaccine (Havrix)?

For IM administration.

• The preferred placement is the deltoid muscle.
• Avoid administering to the gluteal area due to diminished effectiveness.
• Subcutaneous, intradermal, or intravenous administration are not acceptable.
• Shake the suspension thoroughly before use; discard if it turns discoloured or is not homogeneous after shaking, or if the vial or syringe has fractures.
• Avoid dilution.
• Use different needles and syringes for each injection; do not combine with other injections or immunizations.
• The patient should be vaccinated while sitting or lying down to prevent injuries caused by syncope.
• Only if the treating physician believes it suitable can the vaccine be given intramuscularly to individuals who are at risk of haemorrhaging after intramuscular injection.
• A vaccination administered intramuscularly can be scheduled soon after an antihemophilic or other comparable therapy is given to the patient.
• Use a fine needle (23 gauge or smaller) and apply firm pressure to the injection site for at least 2 minutes without rubbing.
• The possibility of a hematoma from the injection should be discussed with the patient.
• Patients on anticoagulant therapy should be treated the same as those with clotting factor abnormalities and should be thought of as having the same bleeding risks..

Mechanism of action of Hepatitis A Vaccine (Havrix):

The inactivated hepatitis A vaccine produces active immunity against hepatitis A virus infections.

The beginning of action:

• After the first dose, 95% of adults and 100% after the second develop protective antibodies.
• Within one month, >97% of children or adolescents will become seropositive. After two doses, 100% of them will develop protective antibodies.
• Hepatitis A infection rates among children are 94% to 100% higher in high-infection neighbourhoods than in the suburbs.

Time:

• The vaccine has been shown to produce protective antibodies that last up to 20 years.

International Brand Names of Hepatitis A vaccine:

• Havrix
• VAQTA
• Avaxim
• Avaxim-Pediatric
• HAVRIX
• Avaxim
• Epaxal
• HAVpur
• Havrix
• Havrix 1440
• Havrix Junior
• Havrix Monodose
• Mevac-A
• Vaqta

Hepatitis A Vaccine Brand Names in Pakistan: