A combination vaccine formulation called Twinrix and Twinrix Junior is recommended for active immunisation against hepatitis A and B.

Uses:

• Prevention of diseases like Hep-A and Hep-B

  • Twinrix:
    • Active vaccination of people aged 18 and over (US labelling) or 19 and over (Canadian labelling) against hepatitis A and hepatitis B virus-related illness (including all known subtypes)
  • Labelling according to Canadian standards:
    • Teenagers and kids between the ages of one and fifteen are permitted to receive active vaccinations (not in US labelling).
    • Twinrix Junior [Canadian product]:
      • Between the ages of one and 18, children and teenagers should get an active vaccine against the hepatitis A and B viruses (all known subtypes).
  • Limitations of use: Not used for postexposure prophylaxis

Dose in Adults

Dosage for primary immunization in adults: IM:

• Labelling according to US standards
  • 1 mL was administered 3 times during a period of 0, 1, and 6 months. 
  • Accelerated protocol: 1 mL on days 0 through 7, and days 21 through 30, then a booster at 12 months for a total of 4 doses.
• Canadian labelling: Adults Over 19 years of age (Twinrix):

  • 1 mL was administered 3 times during a period of 0, 1, and 6 months.

  • Accelerated protocol: 4 doses of 1 mL each given on days 0, 7, and 21, plus a booster at 12 months.

Dose in Children

Twinrix (HepA-HepB Vaccine) Dosage for Primary immunization in Children: Canadian labelling: IM:

• Children and Adolescents:

  • Twinrix:
    • Ages 1 to 15: 1 mL administered on the day of choice, followed by a second dosage (1 mL) two treatments spaced 6 to 12 months apart
  • Twinrix Junior:
    • Ages 1 to 18: 0.5 mL administered three times during a period of 0, 1, and 6 months.

Pregnancy Risk Category: C

• The use of the hepatitis A and hepatitis B vaccines by mothers between 2001 and 2015 did not raise the incidence of miscarriage or serious birth abnormalities, according to data from a pregnancy registry.
• The increased danger that inactivated vaccinations provide to the foetus has not been established.

HepA-HepBVirus Vaccine use during breastfeeding:

• It is unknown if this vaccine's components are secreted into breast milk.
• The manufacturer states that the decision about whether to discontinue or continue breastfeeding after immunization is based on the risks to infants, the benefits to the mother, and the effectiveness of the mother's vaccinations.
• The safety of nursing for the mother or the child is unaffected by the medication's administration.

Dose in Kidney Disease:

• No dosage adjustments are provided in the manufacturer's labeling.

Dose in Liver disease:

• No dosage adjustments are provided in the manufacturer's labeling.

The frequency of side effects from the drug combination was comparable to those that followed the administration of the hepatitis A and hepatitis B vaccines separately.

Common Side Effects of Twinrix (HepA-HepB Vaccine):

• Central Nervous System:

  • Headache
  • Fatigue

• Local:

  • Local Soreness/Soreness At Injection Site
  • Erythema At Injection Site

Less Common Side Effects Of Twinrix (HepA-HepB Vaccine):

• Miscellaneous:

  • Fever

• Gastrointestinal:

  • Diarrhea
  • Nausea
  • Vomiting

• Dermatologic:

  • Skin Sclerosis

• Respiratory:

  • Upper Respiratory Tract Infection

• Local:

  • Local Swelling

Contraindications to Twinrix (HepA-HepB Vaccine):

• severe allergic reaction or anaphylaxis after having previously received a dose of either the hepatitis A or hepatitis B vaccine, or after any component of the formulation, such as yeast or neomycin.

Labeling in Canada: Additional contraindications not included in US labelling

• Severe febrile illness.

Warnings and precautions

• Anaphylactoid reactions and hypersensitivity reactions

  • Immediate treatment (including epinephrine 1 mg/mL) for anaphylactoid and/or hypersensitivity reactions should be available during vaccine use.

• 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.

• Acute illness:

  • The need for immunisation is determined by the aetiology and the severity of the symptoms.
  • If a patient has a severe or mild acute sickness (fever or no fever), therapy should be postponed unless they are at risk for hepatitis A and B.
  • Patients with minor acute diseases should receive vaccinations right away, fever or not.

• Bleeding disorders:

  • Patients with bleeding disorders, including thrombocytopenia, should be cautious. Injections may cause bleeding/hematoma.
  • Schedule an IM injection immediately after anti-haemophilia treatment is completed.

Monitoring parameters:

• Monitor for syncope for 15 minutes after administration.
• If seizure-like activity associated with syncope occurs, keep the patient in a supine or Trendelenburg position to maintain adequate cerebral perfusion.

How to administer Twinrix (HepA-HepB Vaccine)?

• IM:
  • Shake violently for 15 to 30 seconds, or until a steady hazy white appearance appears.
  • After shaking, reject any suspension that appears foggy, clear, or unhomogeneous.
  • Use the deltoid area for IM administration rather than the gluteal area (may give a suboptimal response).
  • Not to be given intravenously, topically, or subcutaneously (US labeling).
  • Use different needles and syringes for each injection; avoid mixing vaccinations or injections.
  • Vaccinate while the patient is seated or lying down to prevent syncope-related injuries.
  • For patients at risk of haemorrhage following IM injection, use IM route only at treating clinicians' judgment.
  • Schedule the IM immunisation soon after the patient takes antihemophilic or any related medication.
  • For the immunisation, use a tiny needle (23 gauge or smaller) and push firmly (without rubbing) on the location for at least two minutes.
  • Inform the patient about the possibility of a hematoma following the injection.
  • Anticoagulant treatment patients should be handled similarly to people with clotting factor abnormalities and should be thought of as having the same bleeding risks.
  • The Canadian product labelling recommends that subcutaneous injection can be utilised in individuals at risk for bleeding even though subcutaneous administration is not advised in US labelling (including those with thrombocytopenia).

Mechanism of action of Twinrix (HepA-HepB Vaccine):

• The hepatitis A vaccine offers up to 99% of individuals protection against hepatitis A virus infection (an inactivated viral vaccine).
• The Recombinant Hepatitis B vaccine (NIHV) is a component of the hepatitis B vaccination that was developed from the recombinant DNA-produced hepatitis B antigen (HBsAg).
• It is produced using yeast cells. The hepatitis-B gene encoding for HBsAg is transferred to yeast to produce the hepatitis A vaccine.
• In order to make additional copies, this is done.
• Twinrix, an active vaccine with a >99% effective immune response rate, protects against both hepatitis A and B virus infection in immunocompetent individuals (30 days after completion).
• Comparable to administering the hepatitis A and B vaccinations together.

The beginning of action:

• Antibodies to HAV/HBV were found to have seroconverted one month after the three-dose series was finished.

Duration:

• For more than 15 years in adults and 10 years in children, seropositivity to HBV and HAV has been observed.

International Brands of HepA-HepB Vaccine:

• Twinrix
• Twinrix Junior
• Ambirix

HepA-HepB Virus Vaccine Brand Names in Pakistan:

• No Brands Available in Pakistan.