No recent morbidity and mortality data exist on the most frequent vaccine-preventable diseases (Figure 28.1). The incidence of hepatitis A and typhoid fever has significantly decreased from rates identified in the 1970s and 1980s. Recent estimates are that the incidence of hepatitis A in travellers has fallen 50-fold, with an incidence of the order of 10 to 30 per 100 000 person-months exposed in all travellers^[45] – hepatitis A is the most frequently administered travel vaccine. Typhoid rates are lower by a factor of 10–100 and cholera by a factor of 1000 in comparison to hepatitis A. The risk factors for exposure to these pathogens include duration of stay and hygiene associated with food and beverages (i.e. living with the local population versus in high-class hotels). Previous immunity to hepatitis A can be predicted by the traveller's age, history of previous stays or residence in highly endemic countries, history of jaundice, and immunization …