Nonspecific effects of oral vaccination with live-attenuated Salmonella Typhi strain Ty21a

Sci Adv. 2019 Feb 27;5(2):eaau6849. doi: 10.1126/sciadv.aau6849. eCollection 2019 Feb.

Abstract

Epidemiological and immunological evidence suggests that some vaccines can reduce all-cause mortality through nonspecific changes made to innate immune cells. Here, we present the first data to describe the nonspecific immunological impact of oral vaccination with live-attenuated Salmonella Typhi strain Ty21a. We vaccinated healthy adults with Ty21a and assessed aspects of innate and adaptive immunity over the course of 6 months. Changes to monocyte phenotype/function were observed for at least 3 months. Changes to innate and adaptive immune cell cytokine production in response to stimulation with vaccine and unrelated nonvaccine antigens were observed over the 6-month study period. The changes that we have observed could influence susceptibility to infection through altered immune responses mounted to subsequently encountered pathogens. These changes could influence all-cause mortality.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / metabolism
  • Cytokines / metabolism
  • Female
  • Healthy Volunteers
  • Humans
  • Male
  • Middle Aged
  • Monocytes / immunology
  • Monocytes / metabolism
  • Polysaccharides, Bacterial / administration & dosage
  • Polysaccharides, Bacterial / immunology*
  • Salmonella typhi / immunology*
  • Typhoid Fever / immunology
  • Typhoid Fever / metabolism
  • Typhoid Fever / prevention & control*
  • Typhoid-Paratyphoid Vaccines / administration & dosage
  • Typhoid-Paratyphoid Vaccines / immunology*
  • Vaccination*
  • Vaccines, Attenuated / administration & dosage
  • Vaccines, Attenuated / immunology*
  • Young Adult

Substances

  • Cytokines
  • Polysaccharides, Bacterial
  • Ty21a typhoid vaccine
  • Typhoid-Paratyphoid Vaccines
  • Vaccines, Attenuated