Change of Mind: Vaccines Now to be Used for Cholera Control in Haiti

| January 31, 2012 | 0 Comments

By Mathieu Maheu-Giroux

The cholera epidemic in Haiti is currently the largest in the world with more than 515,699 reported cases and 6,942 dead (as of 11/30/2011). Since the beginning of the outbreak the bulk of relief efforts has been concentrated on timely case management, the distribution of oral rehydration salts, improving water security, and extensive hygiene education campaigns.

Banners displayed during last October 19th demonstration marking the one-year anniversary of the start of the Haitian cholera outbreak. (Photo credit: Ansel Herz 2011.

Immediately after the outbreak was detected in October 2010, an emergency response team was created. Mass immunization with Dukoral, the only cholera vaccine approved by the World Health Organization (WHO) at the time was considered but this option was quickly dismissed. It was felt that the enormous logistical issues associated with setting up an immunization campaign could not be overcome. There was widespread civil unrest and, in the aftermath of the earthquake, the Haitian governance structure was still too weak. More importantly, however, is the fact that the worldwide stockpile of vaccine was only 200,000-300,000 doses at that time – enough to immunize only a fraction of Haiti’s population.

In December 2010, a WHO meeting was convened that revised its recommendations. It called for a small-scale pilot vaccination program with Dukoral as the situation in the country stabilized. The Haitian government, which was in election mode, wanted immediate scale-up of the program, as it feared a backlash and riots from citizens that would not be targeted by the immunization campaign.

With the WHO’s approval of the Sanchol vaccine on September 29th, which at 1.85$ per dose is substantially cheaper than Dukoral, there was renewed interests in immunization. Newly elected president, Michel Martlelly, also backed targeted immunization. On October 20th, Dr. Gabriel Timothée, director general of the Ministry of Public Health and Population, announced a pilot immunization campaign to be started in January of 2012.

Boston-based NGO Partners in Health also announced last October the purchase of 200,000 currently available doses of the Sanchol vaccine in the hope of immunizing 100,000 Haitians living in high-risk areas. “What we’re calling for, a year into the epidemic, is a prompt integration of these prevention and care and treatment measures” said Paul Farmer, founder of Partners in Health and University Professor at the Harvard Medical School during a recent press conference (10/19/2011). “There’s no argument that this wouldn’t save many thousands of lives and prevent many, many times more new cases”. Cholera vaccines are no magic bullets, though. Efficacy was shown to be only 70% in a trial in India and immunity generally wanes after 2.5 years. Still, results from a mathematical model developed by Jason Andrews from Harvard School of Public Health showed that achieving 10% coverage could avert 63,000 cases and 900 deaths.

After a century of absence on the island of Hispaniola, officials are recognizing that cholera is now there to stay. Improving water security might be the only long-term measure that will permanently reduce incidence but cholera vaccines might contribute by saving lives in the short term.


Category: Infectious, Online

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