Locally run cholera intervention can reduce disease burden, finds studyBMJ 2015; 350 doi: https://doi.org/10.1136/bmj.h2658 (Published 15 May 2015) Cite this as: BMJ 2015;350:h2658
An oral vaccine against cholera had a protective effectiveness of 69% against clinically significant cholera when administered to a rural population by local health officials and with local resources, found a study carried out in the cholera endemic area of Satyabadi in Odisha state, India.1 The results were similar to those of a controlled clinical trial that used the same vaccine (65% protection over five years).
Published in Vaccine, the study involved 31 552 people who received at least a single dose and 23 751 who received two doses of the vaccine Shanchol. Prequalified by the World Health Organization and locally licensed, Shanchol is a modified, killed, bivalent, whole cell vaccine that is given as two doses, a minimum of 14 days apart. The vaccine was administered during a mass campaign in May-June 2011, the hottest season of the year, when ambient temperatures can be as high as 42°C.
Researchers used a case-control approach that included only people who sought care for severe diarrhoea. The cases were people who tested positive for Vibrio cholerae, while controls were those who tested negative for the bacterium.
Over the next two years researchers identified 44 cases and 366 controls. The adjusted vaccine effectiveness for those who received two doses was 69% (95% confidence interval 14.5% to 88.8%) in comparison with controls. With only a single dose, the vaccine’s effectiveness was not significant at 32.5%.
The study’s lead author, Thomas Wierzba, senior scientist at the International Vaccine Initiative in Seoul, South Korea, said that the vaccine should be integrated into the government’s regular vaccination programmes. Government health staff should not wait for an outbreak, he said, and campaigns should be conducted every three to five years wherever cholera cases occur.
Cite this as: BMJ 2015;350:h2658