Safety and immunogenicity of an oral, inactivated enterotoxigenic Escherichia coli plus cholera toxin B subunit vaccine in Bangladeshi adults and children.
We have compared the B cell responses evoked in Bangladeshi, adults (n=11, median age 25 years) and children (n=21, median age 4.5 years), 7 days after intake of each of two doses of an oral, inactivated enterotoxigenic Escherichia coli (ETEC) vaccine composed of formalin-killed ETEC strains expressing the colonization factors, CFA/I, CFA/II and CFA/IV together with 1 mg of recombinant cholera toxin B-subunit (rCTB). The vaccine was well tolerated and only gave rise to negligible side effects. Peak antibody-secreting cell (ASC) response of the IgA isotype were seen 7 days after the first dose of the vaccine. The ASC responses to the different colonization factors (CFs) increased from a 29- to 46-fold (responder frequency 90-100%) in the adults and 13- to 24-fold (responder frequency 67-90%) in the children. The IgA-ASC response to rCTB also peaked after the first dose in the adults (426-fold, responder frequency 100%) and the children (46-fold, responder frequency 95%). Increased IgA antibody levels against CFA/I as well as IgA and IgG antibody levels to rCTB were seen in plasma after immunisation. About 86% of the children and 80% of the adults responded with faecal antibodies to rCTB, whereas about 67% of both groups responded to CFA/I. These results show that a single dose of the ETEC vaccine may elicit significant mucosal immune responses in both children and adults residing in an ETEC-endemic country such as Bangladesh.
Qadri
F
F
International Centre for Diarrhoeal Disease Research, Bangladesh, GPO Box 128, Dhaka 1000, Bangladesh. fqadri@icddrb.org
Wennerâs
C
C
Ahmed
F
F
Asaduzzaman
M
M
Saha
D
D
Albert
M J
MJ
Sack
R B
RB
Svennerholm
A
A
D000328:Adult; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001428:Bacterial Vaccines / Q000276:immunology*; D001459:Bangladesh; D002648:Child; D002675:Child, Preschool; D002772:Cholera Toxin / Q000276:immunology*; D022121:Cholera Vaccines / Q000276:immunology*; D004341:Drug Evaluation; D004768:Enterotoxins; D004926:Escherichia coli / Q000276:immunology*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis; D008297:Male; D018074:Vaccines, Conjugate / Q000276:immunology
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D022121:Cholera Vaccines; D004768:Enterotoxins; D007070:Immunoglobulin A; D018074:Vaccines, Conjugate; D002772:Cholera Toxin