New Vaccine Shows Promise Against Typhoid and Salmonella in Clinical Trial

Baltimore, MD

Researchers at the University of Maryland School of Medicine’s Center for Vaccine Development and Global Health (CVD) have completed a Phase I clinical trial of a new vaccine aimed at protecting against typhoid fever and invasive non-typhoidal Salmonella, both significant causes of disease in children in sub-Saharan Africa. The trial results were published in a recent issue of a medical journal.

The investigational vaccine, known as the Trivalent Salmonella Conjugate Vaccine (TSCV), is designed using sugars from the outer coating of the Salmonella typhi bacteria and two common types of invasive Salmonella. These sugars are attached to proteins that help the body mount an immune response.

In the randomized, placebo-controlled trial, 22 healthy adults in the U.S. received either a low (6.25 µg) or high dose (12.5 µg) of TSCV or a placebo. The vaccine was found to be safe with minimal side effects, mainly mild and short-lived pain at the injection site. Importantly, all participants who received the vaccine developed robust immune responses, compared to none in the placebo group.

Dr. Wilbur Chen, the study’s lead investigator, expressed optimism about the results, stating, “These results are highly encouraging. They show that TSCV has the potential to protect children in regions where both typhoid and Salmonella are endemic and deadly.”

The vaccine may also help protect against Salmonella infections in the U.S., which cause about 1.35 million illnesses yearly, according to the Centers for Disease Control and Prevention.

Some participants had preexisting antibodies, indicating previous exposure to the bacteria through food, which may enhance the vaccine’s longevity and efficacy. The vaccine also triggered balanced immune responses, highlighting its potential effectiveness.

Dr. Myron Levine, a co-author of the study, noted, “These findings provide a strong foundation for future studies. We plan to investigate how the vaccine performs in young children, the most vulnerable demographic.”

The vaccine development was a collaboration with Bharat Biotech International Limited (BBIL). Dr. Mark T. Gladwin, Dean of the UM School of Medicine, emphasized the urgent need for such a vaccine, referencing over 420,000 cases of Salmonella disease in sub-Saharan Africa in 2017.

A vaccine that protects against both illnesses could significantly impact global pediatric health.