Digital illustration of cholera bacteria
Digital illustration of cholera bacteria

Last October the most powerful Caribbean storm in a decade—Hurricane Matthew—hit Haiti. Hundreds of people died and thousands of homes were destroyed, leaving many people homeless with no reliable food or source of clean water.

Those who survived the storm’s fury were not out of danger, however, as the lack of clean water resulted in the resurgence of an all too familiar threat—cholera.

In 2010, after a devastating earthquake hit Haiti, an outbreak of cholera quickly spread through the island nation. The outbreak affected over 770,000 people and resulted in 9,200 deaths.

With the disruption to the water supply created by Hurricane Matthew last fall, the region of Southern Haiti is confronting the possibility of yet another outbreak.

There is hope for a better outcome this time around, however, as a team of researchers—including Mass General postdoctoral fellow Brie W. Falkard, PhD—have already been working in Haiti to test the effectiveness of a new cholera vaccine.

Brie Falkard

Brie Falkard, PhD, left, is testing the effect of the cholera vaccine in Haiti. (Submitted photo).

ABOUT CHOLERA

Cholera is an acute diarrheal disease that can be lethal if left untreated. It is caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae (V.cholerae). Researchers estimate there are up to four million cases of cholera worldwide each year, and hundreds of deaths occur from the rapid dehydration caused by the disease.

Most people infected with V. cholerae have no or mild symptoms, but they can potentially infect other people since the bacteria remain present in their feces for up to ten days after infection. Thus in areas without sanitary water and sewer conditions, it is easy for the bacteria to move between hosts.

People with mild symptoms can be treated with oral rehydration solution, while the severe cases will need fast treatment with intravenous fluids and antibiotics.


STUDYING THE VACCINE

Since the early 1980s, different oral cholera vaccines have been developed for use in conjunction with improvements in water and sanitation in order to control cholera outbreaks and for prevention in areas known to be high risk for cholera.

Dr. Falkard, a postdoc in laboratory of Jason Harris, MD, in the Division of Infectious Disease at Massachusetts General Hospital, was in Haiti studying one such vaccine when the hurricane hit.

Luckily, the lab where she was working is located at the Hôpital St. Nicholas, a Partners In Health operated hospital in the city of St. Marc, which was not directly impacted by the hurricane. The area was affected with high winds and flooding, but not by massive devastation as in the south of the island.

Brie’s study on a cholera vaccine has now taken on added importance, in order to prevent the current epidemic from spreading and taking more lives.

The study, co-mentored with Louise Ivers, MD, MPH, DTM&H, of Brigham and Women's Hospital and Partners in Health, consists of delivering the licensed vaccine Shanchol®, manufactured by Shantha Biotech in India, to adult participants in Haiti, and then performing a long-term follow-up by collecting blood samples over the course of a year to determine how effective the vaccine is.

The study examines how the vaccine stimulates memory responses to provide optimal dosing and to understand how it generates protection in humans. It complements other cholera work from partners at Zanmi Lasante in Haiti, who provide comprehensive cholera treatment, patient care and diarrheal disease surveillance.

Shanchol is a mix of multiple strains of cholera that have been inactivated by heat and formalin (a water-based solution of formaldehyde). The modifications make the bacteria safe to administer because they are not infective anymore but still generate immune responses to protect against future infections. Thus, it is critical to test the efficacy and the durability of inactivated vaccine in patients.

The World Health Organization (WHO) has approved Shanchol vaccine for international use. So far, it has been tested only in South Asia and it has demonstrated 65% protection for five years after vaccination. Unfortunately, Shanchol doesn’t provide a lifetime protection.

“It is really important to know if Shanchol is effective in the Haitian population and in the climate and conditions of Haiti in order to be able to administer it for epidemic control as a reactive vaccination, or to prevent epidemics from happening in other places where there are similar climate conditions,” says Brie.

LOGISTICAL CHALLENGES

One major challenge of conducting research in Haiti is the country’s limited infrastructure. “It’s a really poor country and in order to get this project to work we had to establish some of the infrastructure by ourselves. Basic things like being able to keep things cold, making sure temperature sensitive samples don’t thaw, making sure that electricity works or to have a backup power; it’s the main challenge.”

Brie said that a lot of the work she has done over the past year is to make the lab fully operational. “Setting up new protocols and pieces of equipment, training a lot of local technicians to run the lab independently.”

MAKING A DIFFERENCE

For Brie, seeing the real-life effects of diseases such as cholera up close is what motivates her to continue her work in challenging locations such as Haiti. “I’m spending a lot of time abroad and knowing that those diseases are impacting people on a daily basis. I get to know people that confront those problems all the time, so it becomes very personal.”

“When I was doing my PhD, I didn’t get to work abroad, so I was missing an understanding of how those diseases are such a problem in people’s lives, how they have to deal with it, how to find solutions that fit in the context of their everyday lives, what it is normally like to live in Africa or South Asia or Haiti. You cannot have a piece of technology that only works in the United States. You have to bring it into the context of the region where you are working.”

While Brie has already been able to make a significant impact in Haiti, she has hopes of making a bigger impact by transitioning to industry following her postdoctoral fellowship.

“I’d love to stay in infectious disease field. I’d love to work on vaccine development and testing. I thought of moving into industry, into a position where I could bridge the gap in translation medicine bench research and human studies for some patients in developing countries.”

This article was written by Carla D'Avanzo, PhD, a communications intern with the Mass General Research Institute as part of a program through the Office of Research Career Development.

Back to Top