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Hepatitis A/B Combo Vaccine (TWINRIX)


Hepatitis A

  1. Hepatitis A is the most commonly indicated vaccine for travel to developing countries, where there may be unsafe food and water due to poor sanitation.
  2. Although children usually have almost uneventful, mild illness with hepatitis A infection, adults may suffer a serious, prolonged course.
  3. Almost everyone who has lived in a developing country without prior vaccination will have acquired hepatitis A virus, and so will have lifelong, natural immunity. This can be verified with a blood test for hepatitis A IgG antibody, making the need for the vaccine unnecessary.


Hepatitis B

  1. Hepatitis B is NOT easily acquired. It is a body fluid/bloodborne virus, and so vaccination is considered in special travel circumstances,
    1. When unsafe sex is practiced
    2. Where exposure to re-used, blood contaminated medical equipment and blood products for transfusion is possible through local medical care (developing countries)
    3. Where work assignment might expose one to wounds and body fluids of co-workers
  2. Blood tests can be done prior to vaccination to see if Hepatitis B vaccine is needed.


Hepatitis A


Disease: Hepatitis A virus inflames the liver, causing generalized misery for weeks in adults, but usually minor or unnoticeable clinical illness in young people.

Common Symptoms,

  1. Flu-like illness (without the respiratory symptoms)
  2. Fever
  3. Poor Appetite
  4. Muscle/Joint Aches
  5. Abdominal Pain
  6. Jaundice (yellow eyes/skin/urine)
  • Incubation: from exposure to illness = 15-50 days (avg = 4 weeks)
  • Illness duration = 1-2 months
  • Only 3-6/1000 cases are fatal
  • Hepatitis A virus does not cause permanent liver damage



  • Worldwide, but most prevalent in developing countries
  • Risk increases with extended and rural travel.



  • Person-to-person through fecal-oral route
  • So, hepatitis A virus is easily passed through household contacts and public exposure to fecally contaminated food and water, most commonly ice, unpeeled fruits/vegetables, and raw/undercooked shellfish.

Hepatitis A virus Treatment: None



  1. Water chlorination
  2. Boiling water or cooking over 185°F for 1 minute
  3. Strict water and food restriction during travel
  4. Avoid uncooked food, salads, pudding, watermelon
  5. Only canned or bottled drinks
  6. Fruits and vegetables you peel yourself
  7. Use only ice cubes from purified water
  8. Only well-cooked meat and seafood
  9. Hepatitis A virus Vaccine
    1. Optimally, at least 1 month pre-travel
    2. 2 doses, 6-12 months apart
    3. Lifelong immunity likely
    4. Combination hepatitis A/B vaccine = Twinrix
      1. 3 doses: 0, 1, 6 months
    5. Vaccine Targets
      1. Travelers to underdeveloped countries
      2. Homosexuals
      3. Illicit drug users
      4. Chronic liver disease patients
      5. Households adopting children from countries with prevalent hepatitis A virus
      6. Patients who receive blood clotting factor concentrates (hemophiliacs)
      7. Hepatitis A vaccine: Children ≥ 1 year-old
      8. Twinrix: > 18 yrs-old
    6. Vaccine Cautions
      1. Those with life-threatening reactions to components of some hepatitis A virus vaccine brands and Twinrix : aluminum, aluminum hydroxide, 2-phenoxyethanol, latex, neomycin, yeast, formalin (check each product for which of these pertain)
      2. Delay vaccination if moderately ill until recovered.
      3. Side-Effects: Uncommon and last 1-2 days
        1. Injection site soreness
        2. Headache
        3. Poor appetite
        4. Fatigue
      4. Safety in pregnancy has not been proven, but, as a killed vaccine, it is unlikely a risk to a fetus.


Hepatitis B

Disease: Inflammation of the liver by hepatitis B virus (HBV)

Like hepatitis A, adults often (50%) are quite ill, but not children. Unlike hepatitis A, a substantial percentage of hepatitis B virus infections cause chronic disease.

Acute (short-term) Illness:

  1. Fever
  2. Poor Appetite
  3. Muscle/Joint Aches
  4. Abdominal Pain
  5. Nausea
  6. Diarrhea
  7. Jaundice (yellow eyes, skin, urine)
  8. Fatigue

Chronic Illness:

  1. Cirrhosis (liver damage)
  2. Liver cancer
  3. Death
  4. Chronic hepatitis B virus carrier (infectious to others)

Average incubation is 90 days (range 60-150 days).

Prevalence: Worldwide, but more so in developing countries



  1. Body Fluids (blood, sexual)
  2. Hepatitis B virus can live on a contaminated object up to 7 days (razor blades, toothbrushes, needles, etc).
  3. Blood transfusion products
  4. Special Risk Groups
    1. Travelers
    2. Prolonged stay or frequent travel
    3. New sexual contact(s) during trip
    4. High potential for medical or dental care in local facilities,
      1. Travelers with underlying medical illness/conditions
      2. Traveling to obtain medical/dental services
      3. Adventure travelers
      4. Travelers using local public transportation extensively
      5. Travelers receiving tattoos, acupuncture, or body piercing
    5. Healthcare workers


Treatment: Antiviral drugs for Hepatitis B virus



  1. Avoid casual sexual contact.
  2. Use latex condoms and vaginal spermicidal jelly for intercourse.
  3. Never share needles, razors, toothbrushes, or medical equipment, like diabetic lancets.
  4. Avoid tattoos, body-piercing, acupuncture.
  5. Avoid medical/dental care abroad, especially involving needles, IV lines, surgery, blood product transfusions.
  6. Hepatitis B virus Vaccine,
  7. The Vaccine
    1. 3 doses: day 1, day 30, then 6-12 months after 1st dose
    2. Optimally, complete first 2 doses a month before travel.
    3. If suffering from a moderately severe illness, delay vaccination until recovered.
    4. Some hepatitis B virus vaccine brand products can cause reactions in those allergic to neomycin, yeast, aluminum, 2-phenoxyethanol, or formalin.
    5. Possible side-effects: Injection site soreness, fever, headache, nausea (all uncommon and brief)
    6. Combination hepatitis A/B vaccine = Twinrix
      1. 3 doses: 0, 1, 6 months
  8. Targeted groups,
    1. International travelers with recurrent travel or prolonged stays in developing countries
    2. Households adopting children from high prevalence hep B countries (check hepatitis B virus status of child with blood testing)
    3. Chronic liver disease patients
    4. End-stage kidney disease (dialysis)
    5. Solid organ transplant candidates
    6. HIV positive
    7. Mentally retarded who are institutionalized
    8. Homosexuals
    9. Sexually polygamous
    10. Healthcare workers or other jobs with body fluid exposure (first-responders)
    11. Diabetics
    12. Twinrix: > 18 yrs-old
      1. Contraindications: Those with life-threatening reactions to components to: latex, neomycin, yeast, aluminum, 2-phenoxyethanol, or formalin.

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