Field trial of oral cholera vaccines in Bangladesh: evaluation of anti-bacterial and anti-toxic breast-milk immunity in response to ingestion of the vaccines.
In a field trial conducted in Bangladesh, ingestion of either B subunit-killed whole cell (BS-WC) or killed whole cell (WC) oral cholera vaccines by mothers was associated with a 47% reduction of the risk of cholera in their non-vaccinated children aged under 36 months. Because vaccine-induced breast-milk immunity seemed a possible explanation for these findings, we evaluated anti-lipopolysaccharide (LPS) and anti-cholera toxin (CT) IgA antibody responses in breast milk collected during the trial from 53 lactating women who ingested three doses of BS-WC, WC, or an Escherichia coli K12 strain (K12). Despite induction of moderate vibriocidal (1.4 to 2.0-fold) and anti-CT (4.5-fold) serum antibody responses, the vaccines did not elicit significant rises of anti-LPS or anti-CT IgA breast-milk antibodies. The failure of the vaccines to elicit significant levels of breast-milk anti-cholera antibodies suggests an alternative explanation for protection of young children by maternal vaccination, such as interruption of maternal-child transmission of Vibrio cholerae 01.
Clemens
J D
JD
International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh.
Sack
D A
DA
Chakraborty
J
J
Rao
M R
MR
Ahmed
F
F
Harris
J R
JR
van Loon
F
F
Khan
M R
MR
Yunis
M
M
Huda
S
S
D000284:Administration, Oral; D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D001459:Bangladesh; D002675:Child, Preschool; D002771:Cholera / Q000276:immunology / Q000517:prevention & control*; D022121:Cholera Vaccines / Q000008:administration & dosage / Q000276:immunology*; D005260:Female; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007070:Immunoglobulin A / Q000737:chemistry / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D008895:Milk, Human / Q000737:chemistry / Q000276:immunology*; D011247:Pregnancy; D012307:Risk Factors; D014611:Vaccination; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology; D014734:Vibrio cholerae / Q000276:immunology
D000907:Antibodies, Bacterial; D022121:Cholera Vaccines; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D015164:Vaccines, Inactivated