Hepatitis A (HepA) and hepatitis B (HepB) remain two
important vaccine-preventable infections in the world. According to WHO
reports, more than 116 countries are currently carrying out universal HepB
vaccination of infants and/or adolescents.
Safe and highly effective vaccines against HepA have been available since 1991. The public health approach to HepA infection traditionally has been one of containment, with most European governments offering the vaccine only during outbreaks and to selected risk groups. This approach is expensive and has serious limitations. Since 1998–1999, several countries and regions – including Israel, Catalonia in Spain, Puglia in Italy and more than 15 US states – have been considering, or have now decided to begin, mass vaccination against HepA because of the local epidemiology of infection.
The availability of a combined HepA plus HepB vaccine means that the HepA prevention programme can now be added readily to the already existing HepB vaccination programme in those countries planning to introduce universal childhood vaccination against HepA. Simplification of the dosage schedule for combined HepA plus HepB vaccination, by reducing the number of doses from three to two, could improve compliance without compromising protection, relative to the traditional vaccination schedule.
Recent vaccine studies have shown that the adult formulation of the combined HepA plus HepB vaccine, given in a two-dose schedule at 0 and 6 months, could be an appropriate alternative for the immunisation of individuals aged 1–18 years. At month 7, 100% of subjects in these studies were seropositive for anti-HepA virus, and more than 98% were seroprotected against HepB virus. A favourable clinical tolerability profile was reported.