A single-dose oral cholera vaccine developed by researchers at Mass General Brigham has shown promising results in a phase 1 clinical trial, according to findings published in The Lancet Infectious Diseases.
Cholera remains a significant global health concern, with up to 4 million cases and approximately 143,000 deaths reported each year. Around 1.3 billion people are estimated to be at risk of contracting the disease, which is caused by ingesting water or food contaminated with Vibrio cholerae bacteria. These bacteria release toxins that can lead to severe vomiting and diarrhea.
The new vaccine, named PanChol, was created from a weakened form of the Vibrio cholerae strain responsible for most current cases worldwide. Researchers modified the strain to ensure safety and prevent it from regaining its ability to produce harmful toxins.
In the phase 1 trial involving 57 participants, different doses of PanChol were tested to determine the optimal amount. Following this initial assessment, some participants received one oral dose of PanChol while others received a placebo.
Safety was the primary focus of this early-stage trial. Adverse events among participants were generally mild and temporary. Whole-genome sequencing performed on samples from vaccinated individuals confirmed that the vaccine remained genetically stable—a key factor for safety assurance. The presence of PanChol in stool samples indicated that the vaccine was replicating as intended in the intestine. All vaccinated participants developed strong immune responses against Vibrio cholerae antigens within two weeks after receiving the vaccine.
"This work represents a significant step forward in our efforts to combat a devastating disease and shows what can be accomplished at MGB given the depth of our scientific talent," said co–senior author Lindsey Baden, MD, vice president of clinical research at Mass General Brigham. "This achievement is a testament to the collaborative spirit among research scientists and clinical trial experts at Mass General Brigham who share a commitment to improving the lives of patients both here and globally."
Researchers plan further testing of PanChol in regions where cholera is more common. A new phase I trial is scheduled to begin in Lusaka, Zambia in early 2026.
