Safety, immunogenicity, and lot stability of the whole cell/recombinant B subunit (WC/rCTB) cholera vaccine in Peruvian adults and children.
To assess the safety, immunogenicity, and lot stability of the whole cell/recombinant B subunit cholera vaccine, 2 lots manufactured in June 1991 and February 1992 were tested in January 1995. Two oral doses of vaccine or placebo given 2 weeks apart were given with buffer to 216 Peruvian adults and children. Symptoms were elicited for 3 days after each dose. Serum and plasma specimens obtained from each volunteer before vaccination and 10-14 days after the second dose were tested for vibriocidal and anti-cholera toxin antibodies. The vaccine was well-tolerated. Nearly half of the 100 vaccinees had pre-vaccination vibriocidal titers > or = 1:40. Elevated titers were observed in 22% of 37 children 2-5 years of age compared with 66% of 63 vaccinees 6-65 years (P < 0.001). A > or =2-fold serum vibriocidal response was observed in 55% of 100 vaccinees and 6% of 32 placebo recipients. An elevated pre-vaccination titer (< or =1:40) did not change the proportion of vaccinees who responded with a > or =2-fold increase in vibriocidal titer (51% versus 59%, difference not significant), but did change the proportion responding with a > or =4-fold increase (41% versus 22%; P < 0.05). The vibriocidal seroconversion rate was lowest in children 2-5 years old despite low pre-vaccination titers. Two-fold or greater serum antitoxic responses in IgA and IgG were observed in >90% of the vaccinees; > or =4-fold responses were seen in 65-70% of the vaccinees with a 6-8-fold increase over baseline. Plasma specimens were as good as sera for determining anti-toxic antibodies by ELISA, but were less satisfactory for determining vibriocidal antibody titers.
Taylor
D N
DN
Naval Medical Research Institute Detachment, Lima, Peru.
Cárdenas
V
V
Perez
J
J
Puga
R
R
Svennerholm
A M
AM
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood; D002648:Child; D002675:Child, Preschool; D002771:Cholera / Q000517:prevention & control*; D002772:Cholera Toxin / Q000276:immunology*; D022121:Cholera Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D004311:Double-Blind Method; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010568:Peru; D012016:Reference Values; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D014734:Vibrio cholerae / Q000276:immunology* / Q000302:isolation & purification
D000907:Antibodies, Bacterial; D022121:Cholera Vaccines; D014614:Vaccines, Synthetic; D002772:Cholera Toxin