How the immune system protects against typhoid and paratyphoid

Immune Mechanisms of Protection in Salmonella Infection in Humans

['FUNDING_R01'] · UNIVERSITY OF MARYLAND BALTIMORE · NIH-11294547

Looking at how adults' immune systems respond to typhoid and paratyphoid bacteria to help create better vaccines.

Quick facts

Phase['FUNDING_R01']
Study typeNih_funding
SexAll
SponsorUNIVERSITY OF MARYLAND BALTIMORE (nih funded)
Locations1 site (BALTIMORE, UNITED STATES)
Trial IDNIH-11294547 on ClinicalTrials.gov

What this research studies

You would provide blood and other clinical samples from adults who were exposed to wild-type Salmonella Typhi or Paratyphi A or who received vaccine candidates. Researchers will examine B cells, T cells, antibodies, and innate immune signals in those samples with laboratory tests. They will compare responses from people who were protected versus those who developed disease in controlled human infection models and vaccine studies. The aim is to identify immune markers and mechanisms that guide development of multivalent vaccines, especially against Paratyphi A and drug-resistant strains.

Who could benefit from this research

Good fit: Typical participants are healthy adults aged 21 and older, including volunteers from regions where enteric fever is common or adults who have provided samples after infection or vaccination.

Not a fit: Children, pregnant people, and severely immunocompromised individuals are generally excluded and would not directly benefit from participation.

Why it matters

Potential benefit: If successful, this work could speed development of vaccines that prevent typhoid and paratyphoid and reduce antibiotic-resistant infections.

How similar studies have performed: Previous work, including studies of the licensed Ty21a vaccine and controlled human infection models, has identified immune responses linked to protection, but vaccines targeting Paratyphi A are still limited.

Where this research is happening

BALTIMORE, UNITED STATES

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.

View on NIH RePORTER →

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.