Hepatitis A+B vaccine contains paediatric dose of Hepatitis A and adult dose of Hepatitis B.

The standard Twinrix (HepA‑HepB) series consists of three intramuscular doses at 0, 1, and 6 months. Minimum intervals:

• Between Dose 1 and Dose 2: at least 4 weeks (28 days)
• Between Dose 2 and Dose 3: at least 5 months (~20 weeks)

These intervals ensure optimal immune response to both hepatitis A and B.

For rapid protection (e.g., imminent travel), an accelerated 4‑dose schedule may be used: First dose: Day 0 Second dose: Day 7 Third dose: Day 21–30 Fourth (booster) dose: ≥12 months after the first dose This regimen provides earlier protection when the routine schedule cannot be completed before exposure.

If Twinrix is started but completion with single‑antigen vaccines is needed: If 1 dose of Twinrix was given: Complete with 2 adult doses of Hepatitis A (HepA) Complete with 2 adult doses of Hepatitis B (HepB) If 2 doses of Twinrix were given: Complete with 1 adult dose of HepA Complete with 1 adult dose of HepB

• Each Twinrix dose contains an adult dose of HepB and a paediatric dose of HepA.
• A Twinrix dose can substitute for any dose in the HepB series, but not for a full adult dose in the HepA series.
• Any combination of 3 doses of adult HepB or 3 doses of Twinrix constitutes a complete HepB series.
• 1 Twinrix dose + 2 adult HepA doses = complete HepA series.
• 2 Twinrix doses + 1 adult HepA dose = complete HepA series.

Reference: Immunize.org – HepA‑HepB (Twinrix) guidance