Vaccination Against Cholera Could Prevent Long-Term Epidemic in Yemen
PIH expert shares lessons learned from battling cholera in Haiti for past eight years
Yemenis face a dire struggle. As the New York Times reported recently, cholera has killed nearly 2,000 people and infected more than a half million in three short months. That makes the Yemeni outbreak one of the worst of the past 50 years, right up there with Haiti’s.
Cholera is one more burden born by Yemenis, whose country is embroiled in a three-year war between Shia Houthi rebels and Saudi Arabia-backed government forces that, so far, has killed 10,000 people. Public employees haven’t been paid in months. Malnutrition is rampant. Ports and airports are closed, blocking the passage of goods, medicine, and humanitarian aid to those most in need. The United Nations called the situation the world’s largest humanitarian crisis, with 10 million people in need of emergency assistance.
Partners In Health does not work in Yemen, nor does the global health organization have any previous experience in the country. However, we hope that our experience battling Haiti’s epidemic could serve as lessons to avoid repeated mistakes — and more loss of life.
First, there should be universal agreement on how to properly address a cholera outbreak, says Dr. Louise Ivers, executive director of the Center for Global Health at Massachusetts General Hospital and PIH’s senior health and policy advisor. She pointed to a recent failed attempt to deploy 500,000 cholera vaccines in Yemen. The shipment was en route in mid-June, but was sent back because of “security issues, challenges in distribution and administration, and the sheer scale of the epidemic (the vaccine can only be given to uninfected individuals),” according to an editorial in the medical journal, Lancet Gatroenterology & Hepatology.
While security issues would clearly be a challenge for any implementation, Ivers is concerned about some of the claims, saying it’s “difficult to comprehend” how the sheer scale of the outbreak would be one reason to postpone or cancel a proper public health response.
“The scale of the outbreak is exactly a reason that one would want to use vaccination as part of a comprehensive approach — using all of the tools that are available,” Ivers says.
Also, there is no evidence to support the statement that the vaccine can only be given to “uninfected individuals,” she says, nor are there immunological or epidemiological reasons why infected people could not be vaccinated. In reality, the risk of becoming infected is highest during outbreaks, and people exposed to infected cases benefit most from vaccinations.
“Misinformation about cholera vaccine in outbreaks led to missed opportunities in Haiti,” Ivers adds, “and now, according to the statements, appears to be at least partly contributing to cancellation of the vaccination campaign in Yemen.”
For Ivers and the PIH team, the reluctance to use cholera vaccine is familiar. Haiti, where PIH has worked for the past three decades, is fast approaching its eighth year battling cholera, which has infected at least 800,000 people and killed 10,000. Sadly, those numbers will increase. The bacterial disease continues to affect the country — especially the poorest and most vulnerable — mostly because promised water and sewage systems have yet to be built to replace contaminated water sources.
PIH has been at the epidemic’s frontlines since October 2010, when cholera was first diagnosed among patients near St. Marc. Alongside colleagues in the Ministry of Health, Haitian PIH clinicians and staff have treated the sick, helped vaccinate hundreds of thousands of people, built safe latrines, distributed water purification tablets, and educated communities on how to prevent the disease’s spread. While health care providers no longer face a daily surge of cholera patients, as they did at the outbreak, they remain frustrated by the disease’s persistent grip on communities throughout the country.
Ivers remembers Haiti in late 2010, when vaccination campaigns were delayed for more than 18 months, by which time cholera had become endemic. The myth that it is not recommended to vaccinate during an outbreak was a major reason why international “experts” did not support a vaccination campaign at the start of the outbreak.
Whatever the myriad challenges in Yemen that are facing the government and local and international responders, it’s important that decisions not be made due to a lack of understanding of the science, Ivers says, or a lack of knowledge of the successful experience using cholera vaccines globally over the last seven years.
Current relief efforts in Yemen are focused on providing clean water to 16 million people, delivering food aid, and treating those already sick with cholera. Focusing cholera prevention activities on water and hygiene is not enough when other tools are available, in Ivers’ opinion. Tackling a cholera epidemic demands a two-pronged approach. In the short term, identify cases, treat the sick, provide emergency safe water, provide access for good hygiene measures, and vaccinate the population. Vaccination has proven highly effective in Haiti in protecting the most vulnerable from cholera while much-awaited water and sanitation infrastructure is built.
Over the long term, achieving the United Nation’s Sustainable Development Goal 6, access to water and sanitation, for Yemenis (and Haitians) will eliminate transmission of not just cholera, but other water-borne diseases. Water and sanitation infrastructure provide many social goods, but are difficult to institute immediately. Regular bombing attacks targeting infrastructure will make that a continued challenge in Yemen.
“The immediate provision of clean water for all is logistically extremely challenging,” Ivers says, “and vaccination can quickly and relatively inexpensively bridge a gap while those efforts are scaled up.”