London School of Hygiene & Tropical Medicine

School experts have welcomed the results of the first real-life trial of an oral cholera vaccine conducted by researchers in Bangladesh.

An oral cholera vaccine (Shanchol) given as part of routine health services was found to be safe and protect against severe cholera in children and adults in urban Bangladesh where the disease is endemic. The trial results are published in The Lancet.

The findings lend support to the use of the vaccine in routine mass vaccination programmes to help to control cholera in endemic countries, where around 2.8 million cases and 91000 deaths occur every year as a result of the disease.

The study shows that even with moderate vaccination coverage, cases of severe, life-threatening cholera were reduced by nearly 40% among the vaccinated, including children aged 5 years and under who are especially vulnerable to severe cholera. Almost 270,000 residents from high-risk urban slum areas were included in the trial, which provides valuable information about the vaccine's feasibility and effectiveness in a real-life setting for the first time.

Writing in a comment piece in The Lancet, Maureen O'Leary and Professor Kim Mulholland from the London School of Hygiene & Tropical Medicine, said: "This study shows that a population-based vaccination programme, even in populations with high exposure to cholera and with moderate coverage, could substantially reduce the burden of disease associated with cholera (although less than in previous projections ) and would greatly help to control the disease.

"Ongoing monitoring to assess the duration of protection should be an essential component of any mass vaccination programme, to inform the need for booster doses and to evaluate intervention cost-effectiveness.

"Furthermore, oral cholera vaccine is only one part of the larger programme needed to control cholera. It should not supersede efforts to reduce risky behaviours, and to improve sanitation and provide safe drinking water to people living in cholera-endemic areas."

Publication:

M aureen O'Leary and Kim Mulholland. Oral cholera vaccines in endemic countries. The Lancet. DOI: 10.1016/S0140-6736(15)61140-0