Oral cholera vaccines prevent up to 60 percent of new cases

In the first two years after vaccination, oral vaccines have been proven to prevent up to 60 percent of new cholera cases, a new review has revealed.

Researchers for the review examined 40 studies that looked at the effect of cholera vaccinations incorporated into a routine vaccine schedule in areas of the world where the disease is prevalent, according to

For the review, the authors looked at the four largest studies, which included a total of almost 250,000 participants.

The vaccines were shown to provide adequate protection within one month of vaccination, but data from other studies still suggests that protection is unlikely to last more than three years, according to David Sinclair of the Liverpool School of Tropical Medicine in the United Kingdom, reports.

Sinclair and his colleagues also run the International Center for Diarrheal Disease Research in Bangladesh.

"Booster doses in line with the manufacturers' recommendations will be required and the vaccines appear to be safe and not linked to any serious side effects,” Sinclair said, according to

In the studies, the vaccines were made from dead, whole-cell cholera. With use, the number of cholera cases among the participants dropped by 52 percent in the first year and fell an additional 62 percent in the second year. Among children, the number of cases fell by 38 percent.

"There is little direct evidence on the use of these vaccines once an epidemic has actually started, but it is likely that cholera vaccines would have an important impact on reducing disease in epidemics, especially where access to clean water and sanitation is difficult to achieve," Sinclair said, according to

Peter Hotez is the president of the American Society of Tropical Medicine and Hygiene and an infectious disease researcher at The George Washington University.

"Given the protracted nature of cholera outbreaks globally, this affords an opportunity to reconsider use of cholera vaccines in so-called 'reactive' situations, such as the one now in Haiti," Hotez said, according to

The review appears in the latest issue of the Cochrane Library, a publication of the Cochrane Collaboration. The Cochrane Collaboration is an international organization dedicated to evaluating medical research.