Research conducted by European investigators suggests that prevention of both hepatitis A and B infection, compared with preventing hepatitis B alone, is cost effective in the two countries studied. The investigators note that the combined vaccination strategy is likely to have an even greater impact in countries with a higher incidence of hepatitis A infection. Data from this study were presented at the ISPOR 2nd Annual European Conference,*together with data from another study comparing the efficacy and costs of combined hepatitis A and B vaccination in two age groups.