Development of a bead immunoassay to measure Vi polysaccharide-specific serum IgG after vaccination with the Salmonella enterica serovar Typhi Vi polysaccharide.

Journal Article (Journal Article)

Vi polysaccharide from Salmonella enterica serotype Typhi is used as one of the available vaccines to prevent typhoid fever. Measurement of Vi-specific serum antibodies after vaccination with Vi polysaccharide by enzyme-linked immunosorbent assay (ELISA) may be complicated due to poor binding of the Vi polysaccharide to ELISA plates resulting in poor reproducibility of measured antibody responses. We chemically conjugated Vi polysaccharide to fluorescent beads and performed studies to determine if a bead-based immunoassay provided a reproducible method to measure vaccine-induced anti-Vi serum IgG antibodies. Compared to ELISA, the Vi bead immunoassay had a lower background and therefore a greater signal-to-noise ratio. The Vi bead immunoassay was used to evaluate serum anti-Vi IgG in 996 subjects from the city of Kolkata, India, before and after vaccination. Due to the location being one where Salmonella serotype Typhi is endemic, approximately 45% of the subjects had protective levels of anti-Vi serum IgG (i.e., 1 microg/ml anti-Vi IgG) before vaccination, and nearly 98% of the subjects had protective levels of anti-Vi serum IgG after vaccination. Our results demonstrate that a bead-based immunoassay provides an effective, reproducible method to measure serum anti-Vi IgG responses before and after vaccination with the Vi polysaccharide vaccine.

Full Text

Duke Authors

Cited Authors

  • Staats, HF; Kirwan, SM; Whisnant, CC; Stephenson, JL; Wagener, DK; Majumder, PP

Published Date

  • March 2010

Published In

Volume / Issue

  • 17 / 3

Start / End Page

  • 412 - 419

PubMed ID

  • 20107010

Pubmed Central ID

  • PMC2837971

Electronic International Standard Serial Number (EISSN)

  • 1556-679X

Digital Object Identifier (DOI)

  • 10.1128/CVI.00354-09


  • eng

Conference Location

  • United States