Protection against human and porcine enterotoxigenic strains of Escherichia coli in rats immunized with a cross-linked toxoid vaccine
Article
Klipstein, FA, Engert, RF, Clements, JD et al. (1983). Protection against human and porcine enterotoxigenic strains of Escherichia coli in rats immunized with a cross-linked toxoid vaccine
. INFECTION AND IMMUNITY, 40(3), 924-929. 10.1128/iai.40.3.924-929.1983
Klipstein, FA, Engert, RF, Clements, JD et al. (1983). Protection against human and porcine enterotoxigenic strains of Escherichia coli in rats immunized with a cross-linked toxoid vaccine
. INFECTION AND IMMUNITY, 40(3), 924-929. 10.1128/iai.40.3.924-929.1983
To compare their relative immunogenicities, we used synthetically produced Escherichia coli heat-stable toxin coupled to a protein carrier and the B subunit of porcine heat-labile toxin separately in graded dosages to immunize rats. Equivalent antigen unit dosages of each toxin raised approximately the same level of mucosal immunoglobulin A (IgA) antitoxin response and degree of protection against a challenge with respective heat-stable- or heat-labile-toxin-producing viable bacteria. Conjugation conditions were identified, therefore, which yielded a vaccine of these toxins, cross-linked by the carbodiimide reaction, that consisted of equal antigenic proportions of each toxin component as determined by enzyme-linked immunosorbent assay and expressed in antigen units. The dose-related response to immunization with this vaccine was the same as the response to its components given separately. The toxicity of the heat-stable toxin component was reduced <600-fold. Immunization with optimal antigen unit dosages of the vaccine gave greater than or equal to sixfold increases in mucosal IgA antitoxin titers and provided significant (P < 0.001) protection against challenge with heterologous serotypes of viable strains, of either human or porcine origin, that produce heat-stable or heat-labile toxin or both.