Following a meeting of health experts from Asia, members from eight countries in South and Southeast Asia released an advocacy document highlighting the need for an integrated program for cholera control which includes the use of oral cholera vaccines (OCVs) in countries at risk.

Released by the Initiative against Diarrheal and Enteric diseases in Asia (IDEA), an independent, multi-disciplinary group of Asian health professionals working on the surveillance, control, and prevention of cholera and other enteric diseases, the document proposes three critical interventions as part of a comprehensive strategy:

1) Continuous improvement of safe water and sanitation,

2) Establishment or strengthening of effective surveillance systems, and

3) Use of vaccination as a complementary weapon in at-risk populations.

This document is intended for use by national and local health officials, policymakers, and health professionals. Download the full document to learn more.

Cholera is a disease that disproportionately affects the poor; their needs are overlooked because they lack strong advocates like those from which the more affluent can benefit. Cholera is traditionally controlled by good sanitation, access to clean water, and personal hygiene. However, these measures are not always available in slums or in far-flung areas where water supply is not assured and latrines not widely available. Moreover, there may not be enough money to buy soap for personal hygiene in these areas. 

In Asia, cholera is not routinely identified; rather, it is lumped together with other diarrheal diseases under a broad category of “severe watery diarrhea,” largely because of the stigma attached with the disease. Perceived to be a disease found only in unclean environments, government officials may hesitate in the open reporting advocated by the 2005 International Health Regulations. For emerging economies dependent on trade and tourism, fear of embargoes and travel restrictions hinder open acknowledgement of the disease.

Furthermore, cholera identification requires bacteriologic laboratories that may not be available in affected areas; thus when the disease is eventually detected, explosive outbreaks have already occurred, taxing an already overburdened weak public health infrastructure. Since cholera affects mostly the poor who seek care in public clinics and hospitals, private physicians rarely recognize the disease due to their belief that cholera is controlled in their areas.

OCVs have been available for many decades, and yet their use as an additional measure for cholera control has only been recommended recently. Surprisingly, Bangladesh, the country where the first large-scale oral cholera vaccine trial was conducted in 1986, only recently began using OCVs in their public health program. Other mass campaigns have recently been conducted in Africa , Latin America, and Asia. Perhaps this is the beginning of more widespread use of OCV in cholera-burdened countries.

The IDEA advocacy document released by a group of experts from countries that are most affected by cholera adds another voice to the growing clamor for coordinated approaches for cholera control.

There have been several recent important events in oral cholera vaccination.

First, after many years of Dukoral™ being the only World Health Organization (WHO) prequalified oral cholera vaccine (OCV), Shanchol™, a second vaccine that is cheaper and easier to administer, has become available.

Second, the WHO has revised its previous guidelines and now advocates oral cholera vaccination in conjunction with other cholera prevention and control strategies in endemic areas and where there is a risk for cholera outbreaks. Third, an OCV stockpile has now been developed with an initial two million doses to be available for epidemic response in low-income countries. Finally, the GAVI Alliance Board approved a contribution towards the stockpile to increase access to OCVs.

At a November 2013 gathering of public health experts with experience in implementing mass vaccination campaigns, the remaining obstacles to more widespread use of oral cholera vaccination were discussed.

For Asian countries, which have been battling cholera continuously, many experts suggested that there is a need to undo the previous WHO recommendations and to convince policy makers to consider oral cholera vaccination in endemic sites and during outbreaks.

In the African setting, the situation is different. Following a hundred-year absence, cholera returned to Africa in the 1970s. The experts observed that the disease is more openly reported in Africa than in Asia, and many African policy makers are receptive to OCV use. In contrast to Asia, the African policy makers’ concerns center on how, when, and where the vaccine should be deployed, how much it would cost, and how the efforts can be sustained.

There was a consensus among the experts that with more advocacy for the use of oral cholera vaccines, increased dissemination of clear and detailed guidelines on its deployment, and better vaccine supply (including the availability of Shanchol™, development of a stockpile, and GAVI support), it is just a matter of time before oral cholera vaccines become more widely used. For populations with on-going cholera outbreaks, however, that time may be too long. 

Photo: In the Mohammadpur slum in Dhaka, Bangladesh, a boy drinks water from a pipe protruding from the ground among trash that has collected in the area when the water level decreased after the summer monsoon flooding. When the water level is higher, the pipe is immersed in dirty water, contaminating this source of drinking water. © 2010 Zaynah Chowdhury, Courtesy of Photoshare

The November 22, 2013 GAVI decision to commit funds to the stockpile of oral cholera vaccines (OCVs) is a huge step in the eventual control of this disease, which infects 2-3 million persons each year and kills over 100,000.

In 2010, the World Health Organization (WHO) revised its policy regarding the cholera vaccine and now recommends that it be used for countries with cholera and for areas at risk. In 2013, the WHO established a stockpile of 2 million OCV doses to be used in emergency situations. With its most recent announcement, GAVI has committed to increasing the size of the stockpile to make this vaccine more available and affordable to the poor countries which really need it. Although there is still not enough vaccine available to support the inclusion of the vaccine in integrated cholera control programs, this is a major step toward the eventual control of cholera.

Prior to this announcement by GAVI, manufacturers produced only small amounts of OCVs because they were not certain if there would be a demand.  With such small inventories, there was never enough of the vaccine for emergencies, such as the recent cholera outbreak in Haiti. Public health officials, seeing this shortage, would then not place vaccine orders, creating a vicious cycle of low supply leading to low demand. GAVI’s decision will hopefully interrupt this cycle by addressing the issue of low supply, which should then generate more demand; ultimately this will support the effective introduction of the vaccine into integrated cholera control programs.

Having a vaccine available is only one part of the cholera control effort, but it is a critical one. In addition increased immunization with the cholera vaccine, we can anticipate that the greater availability of the vaccine will have several additional benefits:

• Increased stock of vaccine should encourage countries to improve their cholera surveillance so they know when and where to use the vaccine.
• Improved cholera surveillance should improve reporting of cholera cases.
• Improved cholera surveillance will facilitate better and timelier cholera case management, which can result in lower case fatality rates.
• Increased cholera surveillance should also stimulate targeted improvements in water and sanitation by highlighting areas most at risk for this waterborne disease.
• As countries improve their understanding of cholera risk, they can develop comprehensive control plans which will begin to “shrink the cholera map” in their countries.

In summary, this safe and effective vaccine, at a cost of $1.85 per dose, may do much more than protect the persons who take it. It may also help stimulate a range of activities that come together under an improved and integrated cholera control strategy, bringing the world one step closer to the control of cholera.

Learn more about the OCV stockpile, including guidance on how to access the stockpile.