Safety And Immunogenicity Of A Polyvalent Escherichia Coli Vaccine In Human Volunteers

Abstract

Since a limited number of 0 serogroups account for nearly 70% of bacteremic and meningitic Escherichia coli isolates, a polyvalent vaccine was made by conjugating a Pseudomonas aeruginosa exotoxin A carrier protein to the 0 polysaccharide of 12 serogroups of E. coli (01,02,04,06–08,012,015,016,018,025,075). No serious reactions occurred in 88 vaccinees. Fourfold or greater increases in ELISA antibody levels over baseline were greatest (>60% of vaccinees) for 01,02,06–08 and 015; intermediate (∼50%) for 018 and 075, and poorest (≥45%) for 04, 012, 016, and 025. Responses with functionally active opsonophagocytic antibody generally paralleled ELISA antibody responses. With the availability of a safe, immunogenic E. coli vaccine, active and passive immunization strategies merit further development as adjunctive treatment for E. coli bacteremia and neonatal meningitis.