Dual Defense Strategy: New Phase 1 Trial Vaccine Offers Hope Against Invading Salmonella and Typhoid
Scientists have made a promising step towards combating two of the world’s most fatal bacterial infections in children with the creation of a dual vaccine that provides protection against invasive non-typhoidal Salmonella (iNTS) and typhoid fever. They cause high disease and mortality in children and are endemic in the regions of sub-Saharan Africa and certain regions of Asia. There is optimism for greater protection against these deadly pathogens through a new vaccine, based on the findings of the most recent Phase 1 clinical trial.
Understanding the Risk: iNTS and Typhoid
Typhoid Fever: Salmonella typhi infects in order to cause typhoid fever, a systemic infection that is characterized by weakness, abdominal pain, and ongoing fever. It can cause deadly complications and death if left untreated.
Invasive Non-Typhoidal Salmonella (iNTS): iNTS infections, with a majority being caused by Salmonella typhimurium and Salmonella enteritidis, are a common cause of bloodstream infections in children under five years of age. iNTS infections have high mortality because of unmerited delay in diagnosis and therapy.
The Development of the Dual Vaccine: A Joint Venture
The University of Maryland School of Medicine’s Center for Vaccine Development and Global Health (CVD) partnered with Bharat Biotech International Limited to develop the trivalent Salmonella conjugate vaccine (TSVC). The new vaccine offers comprehensive protection against typhoid and iNTS disease by combining elements from current vaccines.
Phase 1 Trial: Promising Results
Study Design: Twenty-two healthy subjects aged 18-45 years were recruited for the Phase 1 study. The subjects were either administered a placebo or received low (6.25 µg) or high (12.5 µg) dosing of the vaccine. The main objectives were to evaluate safety and immunogenicity of the vaccine.
Safety Profile: The dual vaccine was tolerated very well, as attested by the fact that no significant side effects were recorded. The most frequent were mild to moderate and consisted of local injection-site pain and transient fever.
Immune Response: Severe immune activation was depicted by the production of effective serum immunoglobulin G (IgG) responses to the two flagellin proteins and the three targeted polysaccharides by the vaccine.
Implications for Global Health:
The positive outcome of Phase 1 trial is a significant step in the fight against iNTS and typhoid disease. The TSVC may be a valuable component of prevention health care interventions, particularly in endemic areas, if these findings are confirmed in follow-up studies.
A Step Towards Eradication
Typhoid and iNTS vaccine development is a powerful step forward for global health. Immunizing against two major infectious threats with one shot, this technology can contribute to making a substantial impact toward reducing disease burden in risk populations. Successful advancement through the subsequent clinical trial phases and further research must be achieved to deliver this promising dual vaccine to those who need it most.
