The Dukoral vaccine is primarily indicated for the prevention of cholera, which is caused by certain types of E. coli. Its effectiveness against traveler's diarrhea is limited according to the National Institute of Public Health of Quebec. While it may be recommended for individuals at high risk of health complications from traveler's diarrhea, it is not routinely administered to Canadian travelers for this purpose. The most effective prevention for traveler's diarrhea in at-risk countries remains practicing caution with food and water consumption. Antibiotics and other medications for diarrhea can be obtained from a pharmacist to take with you while traveling. If considering Dukoral, it must be prescribed by a nurse or doctor and taken at least 2 weeks before traveling in two doses, with effects lasting for 3 months.