A cheap oral vaccine has prevented cases of deadly cholera in a huge trial in Bangladesh.
The infection is spread through contaminated food or water and causes diarrhoea and severe dehydration.
More than 260,000 people took part in the study, which showed that the vaccine cut cases by 37% and halved the number of the most serious ones.
Experts welcomed the findings, published in the Lancet, but said it was crucial to tackle poor sanitation. (BBC)