LATEST UPDATES » Big Data, Bigger Disease Management and Current preparations to manage the Future Health of Singaporeans       » Big Data in Clinical Research Sector       » Professor Yuk-ling Yung receives Gerard P. Kuiper Prize       » AXA Assistance on Regenerative Medicine       » Singtel – Singapore Cancer Society Race against Cancer 2015       » Jardiance® is the only diabetes medication to show a significant reduction in both cardiovascular risk and cardiovascular death      
Oral cholera vaccine 'offers protection for five years'

Cholera can now be prevented effectively for five years with an oral vaccine, a clinical trial in India has shown.

The oral vaccine Shanchol, manufactured by Shantha Biotechnics of Hyderabad, India, was 65 per cent more effective than a placebo at protecting study subjects from the disease over five years.

With its ability to spread rapidly, cholera can overwhelm public health services and require substantial resources to tackle. African countries alone spent US$156 million on the disease in 2007 alone, according to Berni Nor, a research advisor at the Swedish International Development Cooperation Agency (Sida), which part-funded the vaccine's development.

In 2010, the WHO issued guidance supporting the use of oral cholera vaccines in public health programs in conjunction with other preventative measures such as ensuring access to clean drinking water.

The following year, the organization prequalified Shanchol, allowing trials aimed at getting it licensed for sale to begin. Studies have since shown the vaccine to be effective for up to three years.

Yet the study authors write that its use may be hindered in practice by the "perceived short duration of protection that the vaccine confers" compared with recommended vaccines for other diseases.

One other oral cholera vaccine, called Dukoral, has been prequalified by the WHO, but it is used mainly by Western people travelling to cholera-endemic regions and has not been used by developing nations. Another oral vaccine, mORC-Vax, has also been developed, but this has yet to be prequalified by the WHO.

Long-term study

"Earlier studies on Shanchol showed that, at two years, protective efficacy was 67 per cent; at three years, protective efficacy was 66 per cent. Our study intended to assess the ability of the vaccine to protect against infection for a longer period," says Sekhar Chakrabarti, deputy director of the National Institute of Cholera and Enteric Diseases (NICED) in Kolkata, India, where the studies were conducted from.

The trial involved 66,900 people living in a Kolkata slum. "The participants were given two doses of the vaccine two weeks apart in the period July 2006 to September 2006," says Suman Kanungo, an epidemiologist at NICED and one of the paper's authors.

Over the next five years, those given the vaccine were 65 per cent less likely to have a cholera episode serious enough for them to seek treatment than those given a placebo.

Affordable and accessible vaccine

Shanchol costs US$1.85 a dose, compared with US$5 per dose for its competitor Dukoral, according to Berni Nor. It is also easier to administer than Dukoral, which is sensitive to stomach juices and so has to be taken along with a 'buffer' draught that prevents immediate metabolism of the drug.

"The buffer makes immunization campaigns more difficult logistically," says Nor of Sida.

At present, Shanchol must be used before infection to prevent the disease, but clinical trials are being carried out in Dhaka, Bangladesh, to check its effect on people who already have the disease.

Keya Chaudhuri, a chief scientist at the Indian Institute of Chemical Biology in Kolkata, says she is excited about the extended period of protection that Shanchol provides. But she adds that the vaccine has been primarily tested in places where cholera is endemic and so subjects may already have some immunity to the disease.

"What needs to be tested is how well this vaccine performs on subjects who are not from cholera endemic zones," she points out.

Archita Bhatta
Source: Science Development Network

Click here for the complete issue.

news A Heroic Voyage — Sydney Brenner's Life in Science
news VeloX, A Minimally Invasive Prosthetic Heart Valve for treating Mitral Regurgitation
news Anti-CD25 monoclonal antibody (90Y-daclizumab) a favorable target towards systemic radio-immunotherapy in Hodgkin's Lymphoma

Credits to Sony Computer Entertainment and click here for behind the scenes.

APBN Editorial Calendar 2015
Trends and Predictions for 2015 Robotics in Healthcare Nutrition Universal Health Coverage
Start-Up Biotech Companies Preventative and Translational Medicine Biofuels ASEAN Economic Community and Asia's Life Sciences Industry
Big Data: Healthcare and Drug Development Antibody Engineering in Japan Christmas Edition
APBN Editorial Calendar 2016
Korea's Biotechnology Industry Nutrition and Allergies: Are we, Too Clean? Medical Devices and Technology: Innovation that leaves an Inspiration Tobacco Smoking: The 'Real' Cost of One Cigarette
Life-Saving Opportunities: A Guide to Regenerative Medicine Occupational Health Water Technology Olympics: Evolution of Sports
Respiratory: Seasonal flu viruses
About Us
Available issues
Editorial Board
Letters to Editor
Instructions to Authors
Advertise with Us
World Scientific Publishing Co. Pte. Ltd.
5 Toh Tuck Link, Singapore 596224
Tel: 65-6466-5775
Fax: 65-6467-7667
» Editorial Enquiries: biotech_edit@wspc.com
» For Subscriptions, Advertisements &
   Media Partnerships Enquiries:
   Ms PoPo Kwok or Ms Sok Ching Lim
Copyright© 2015 World Scientific Publishing Co Pte Ltd  •  Privacy Policy