It is an infectious disease caused by the bacterium Vibrio cholerae. Present in much of the world, it is spread through the ingestion of contaminated food or water and causes symptoms such as diarrhea, vomiting and subsequent dehydration.

Although it does not cause symptoms in most infected people, it can be fatal in the most severe cases (with over 100,000 deaths estimated per year). It is endemic in many developing countries, but can cause outbreaks where sanitation conditions are critical, such as following disasters that damage the sewer and water systems.

Children aged 2 to 6 years are given 3 doses, while adults and children older than 6 years are given 2, with a one week interval between doses. The vaccine cycle should be finished at least one week before possible exposure to the virus, and protection lasts 2 years.

The cholera vaccine consists of the inactivated bacterium and subunits of the cholera toxin responsible for symptoms. Taken orally, it stimulates immune defenses in the gut, which fight the toxin and bacteria.