Cholera - An Ongoing Global Health Threat
Cholera continues to be a serious public health issue across many developing regions of the world. Caused by the bacterial infection Vibrio cholerae, cholera is an acute intestinal infection marked by severe diarrhea and dehydration. The disease spreads through contaminated food and water and if left untreated, can be fatal even for healthy adults within hours. According to the World Health Organization (WHO), there are an estimated 1.3 to 4 million cases of cholera globally every year resulting in 21,000 to 143,000 deaths. Cholera remains endemic in over 50 countries, mostly in Africa, Asia and Latin America. Outbreaks are common especially following disasters such as monsoons, cyclones or conflicts where access to clean water is disrupted.
Development of Effective Cholera Vaccines Industry
For over a century, Cholera Vaccines was a disease without a viable vaccine option. This changed in the 1990s with the development and prequalification of two effective oral cholera vaccines - Dukoral by SBL Vaccin and Shanchol by Shantha Biotechnics. Both vaccines use killed whole cell V. cholerae bacteria to provoke an immune response. Clinical trials have shown Dukoral and Shanchol to provide 60-90% protection against cholera for at least 2 years when given orally in a double dose schedule. This represents a major public health tool for cholera control globally.
Large Scale Cholera Vaccines Industry Driving Impact
Since prequalification by WHO in 2001 and 2009 respectively, Dukoral and Shanchol vaccines have been deployed in mass immunization campaigns across cholera endemic regions and in emergency settings during outbreaks to curb transmission and save lives. Over the years, hundreds of millions of doses have been administered globally through both treatment of at-risk groups as well as reactive campaigns following disease outbreaks. Notably in Haiti, the Dominican Republic and Zimbabwe outbreaks were controlled through large scale vaccination drives. Studies assessing the impact of cholera vaccination in various countries have demonstrated 30-90% reduction in cholera cases when immunization coverage exceeds 50%. This public health strategy has helped alleviate suffering greatly in regions heavily impacted by cholera.
Improving Access Through Vaccine Supply and Pricing
While cholera vaccines offer a highly effective disease prevention option, securing adequate and sustained global supply at affordable pricing has remained a challenge limiting broader impact. Dukoral for instance requires extensive production involving centrifugation and purification steps, hiking manufacturing costs. This has kept the vaccine expensive at around $4-6 per dose in the public markets. With support from Gavi, the Vaccine Alliance however, Shantha Biotechnics scaled up low-cost production of the alternate Shanchol vaccine through technology transfer agreements. At $1 per dose, Shanchol has now facilitated vaccination of millions across Africa and Asia through large national and regional immunization drives. Between Shanchol supply and procurement support from WHO, UNICEF and other partners, global cholera vaccine stocks have grown substantially in recent years improving public health access.
Tailoring Vaccine Use Strategies for Maximum Benefit
While vaccines are most impactful against cholera when used preventively in endemic settings or reactively in outbreak contexts, strategies must be tailored to local epidemiology, resources and logistics. Mass campaigns in densely populated urban slums have shown benefit, as have social mobilization drives boosting immunization uptake. Risk-based approaches targeting fishing villages, food handlers or nomadic communities also help curb spread. Oral cholera vaccines may be most useful as part of an integrated prevention package including water, sanitation and hygiene interventions. Vaccines can play an important bridging role until long term WASH infrastructure is established. Strategic use guided by epidemiological surveillance also strengthens disease control programs. Well implemented cholera vaccination alongside timely treatment goes a long way in saving lives from this preventable disease.
Ongoing Collaboration needed to Sustain Progress
Despite advances, cholera continues claiming victims where it remains endemic. Maintaining momentum in the cholera vaccine field demands ongoing global cooperation and investment. Ensuring consistent supply of affordable cholera vaccines will be important to meet escalating global demand driven both by need as well as growing recognition of vaccines as an effective prevention tool. National stockpiling, regional coordination and emergency response preparedness also strengthen public health resilience against disease outbreaks. Continued research into improved formulations, additional prequalified products and strategies to extend vaccine protection duration can further maximize public health impact over time. With committed partnerships between manufacturers, aid agencies, governments and communities, cholera vaccines have potential to curb disease transmission at scale and bring the world closer to controlling this ancient scourge.
Oral cholera vaccines have emerged as an invaluable public health tool for controlling cholera globally. Large vaccination campaigns using affordable Shanchol and other licensed vaccines have saved many lives in endemic areas and outbreak contexts over the past decade. While challenges remain, strategic use of cholera vaccines as part of integrated prevention programs shows promise to limit disease spread substantially. Ongoing collaborative efforts are needed between all stakeholders to sustain progress and realize the full potential of this intervention to alleviate the immense suffering from this preventable disease worldwide.
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