Cholera vaccine could protect communities

A study by Ira Longini and colleagues lends support to the idea that public-health officials should consider mass vaccination in their efforts to control endemic cholera.

Using a mathematical model for cholera transmission based on information from the Matlab region of Bangladesh, the researchers predicted that cholera outbreaks could be controlled by vaccinating as few as half of the population in an affected region.

Because of “herd immunity” (protection of unvaccinated individuals due to the inability of cholera bacteria to reach them via their vaccinated neighbours) the model indicated that vaccinating only 50% of the population could reduce the number of cholera cases among unvaccinated people by 89% and among the entire population by 93%.

With only a third of the population vaccinated, the number of cases of cholera would still be predicted to fall by three-quarters.

The best way to prevent cholera, which is believed to cause about 100,000 deaths per year in developing countries, is to ensure that everyone has access to safe water and good sanitation, but these remain unavailable in many countries, and in situations of population displacement such as refugee camps and disasters such as floods. – (EurekAlert!)

Source: PLoS Medicine