![MSF medical team vaccinating a woman at her home in Bentiu. [Photo by MSF]](https://i0.wp.com/www.sudanspost.com/wp-content/uploads/2025/02/Hepatitis-E_MSF_01.jpg?resize=1000%2C750&quality=89&ssl=1)
The research was conducted by Médecins Sans Frontières (MSF), MSF Epicentre, Johns Hopkins University (JHU), the South Sudanese Ministry of Health, the World Health Organization (WHO), the University of Geneva (UNIGE), and the Geneva University Hospitals (HUG).
Hepatitis E, a viral liver disease transmitted through contaminated water, poses a significant risk in areas with limited access to safe water and sanitation. Outbreaks have frequently occurred in South Sudanese displacement camps.
While a vaccine has been available since 2011, its standard three-dose schedule presents logistical challenges in such settings.
The study assessed the effectiveness of a two-dose vaccination schedule in protecting individuals and controlling an epidemic.
“Symptoms of hepatitis E are similar to other diseases that cause acute jaundice, making it difficult to detect. While we don’t have precise estimates of the global burden, some have put it at around 50,000 deaths a year,” explained Andrew Azman, epidemiologist at the UNIGE-HUG Centre for Emerging Viral Diseases, MSF, and JHU, who led the research.
“The Bentiu camp in South Sudan, home to more than 100,000 people who have been displaced due to civil war, is a regular victim of hepatitis E and other waterborne disease outbreaks, likely due to the poor sanitation conditions and frequent flooding,” the statement found.
The Hecolin vaccine, developed in China, has been recommended by the WHO for outbreak response.
“That’s why it was essential to study the vaccine’s effectiveness on other populations and in regions where the type of virus circulating is different from China, as well as the logistical feasibility of such a campaign,” added Isabella Eckerle, Professor at the Faculty of Medicine and Director of the UNIGE-HUG Centre for Emerging Viral Diseases. “In particular, it was important to understand its effectiveness after just two doses, whereas it is usually administered in three doses 6 months apart.”
The vaccination campaign, targeting individuals aged 16 and older, took place in three rounds in March, April, and October 2022, according to Iza Ciglenecki, Operational research coordinator at MSF Switzerland.
“Our study then compared the vaccination status of 201 patients testing positive for hepatitis E between May and December 2022 with that of others in their neighborhood presenting no symptoms. Despite fewer hepatitis E cases than expected after vaccination, our study revealed that two doses of vaccine was effective, an excellent result given the particular context of a camp for displaced people.”
Samples were analyzed at the Centre for Emerging Viral Diseases.
“These laboratory data, which were challenging to carry out on site, not only demonstrated the protection induced by the vaccine, but also enabled us to better understand transmission and the performance of diagnostic tests, which can help us design better outbreak responses in the future,” emphasized Isabella Eckerle. “This project represents a rewarding synergy between MSF’s operational expertise and our own in translational research and diagnostic excellence!”
The study’s findings, combined with other research, have led to the WHO’s International Coordinating Group (ICG) on Vaccine Provision approving a global stockpile of hepatitis E vaccines for emergencies.
“Our results combined with others helped lead to recent approval by WHO’s International Coordinating Group (ICG) on Vaccine Provision of a stockpile of hepatitis E vaccines for emergencies. This stockpile has the potential to save many lives and we’re looking forward to seeing it in action. These results have also already contributed to the WHO recommendations on the use of a two-dose schedule,” concluded Andrew Azman.
