An inexpensive, little-known cholera vaccine appears to work so well that it can protect entire communities and perhaps head off explosive epidemics like the one that killed nearly 10,000 Haitians in 2010.
The Lancet just published a new study that found that the vaccine gave individuals more than 50 percent protection against cholera and reduced life-threatening episodes of the infection by about 40 percent in Bangladesh, where the disease has persisted for centuries.
In a result that surprised researchers, the vaccine worked far better than supplying families with chlorine for their water and soap for hand-washing.
Cholera, which causes severe diarrhea, kills about 91,000 people a year, most of them children. It is endemic in over 50 countries, mostly in Asia and Africa.
When the infection unexpectedly spreads to a new country where no one has immunity — as it did after Haiti’s 2010 earthquake, and in Zimbabwe in 2008 — it can overwhelm health systems and kill thousands within months.
In Haiti, cholera is presumed to have been introduced by UN peacekeepers from Nepal; it sprang up near sewage leaks from their compound. The disease is widespread in Nepal. If the vaccine had been used as routinely there as it was in this study, experts said, the bacteria might never have reached the Caribbean and many lives would have been spared.
The vaccine, Shanchol, provided 53 percent protection to individuals in the vaccine-only group and 58 percent in those that got it along with chlorine, soap and hand-washing advice.