Safety and immunogenicity of different immunization regimens of CVD 103-HgR live oral cholera vaccine in soldiers and civilians in Thailand.
Attenuated Vibrio cholerae oral vaccine CVD 103-HgR was well tolerated by 324 Thai soldiers and civilians. Most received a single 5 x 10(8) cfu dose, while 40 each received one or two 5 x 10(9) cfu doses. Vibriocidal antibody (the best correlate of immunity) seroconversion was lower in soldiers than civilians (P less than .001). Increasing the vaccine dose to 5 x 10(9) cfu raised the geometric mean titer (P less than .001). A second 5 x 10(9) cfu dose one week later did not notably increase seroconversions. Likelihood of seroconversion was inversely correlated with baseline vibriocidal titer (P less than .001). CVD 103-HgR caused seroconversion in most subjects with baseline titers less than or equal to 1:40, including 100% of civilians after one 5 x 10(8) cfu dose, 79% of soldiers after one 5 x 10(9) cfu dose, and 45% of soldiers after one 5 x 10(8) cfu dose. In persons with elevated baseline titers, vibriocidal antibody seroconversion is not a sensitive measure of whether vaccine has boosted intestinal immunity; for such subjects, other measurements must be used. Study regimens in endemic areas should use a single 5 x 10(9) cfu dose.
Su-Arehawaratana
P
P
Medical Corps, Royal Thai Army, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
Singharaj
P
P
Taylor
D N
DN
Hoge
C
C
Trofa
A
A
Kuvanont
K
K
Migasena
S
S
Pitisuttitham
P
P
Lim
Y L
YL
Losonsky
G
G
D000284:Administration, Oral; D000328:Adult; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood*; D000992:Antitoxins / Q000096:biosynthesis / Q000097:blood; D022121:Cholera Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D003967:Diarrhea / Q000139:chemically induced; D004311:Double-Blind Method; D006801:Humans; D007114:Immunization; D008889:Military Personnel; D013785:Thailand; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D014734:Vibrio cholerae / Q000276:immunology*
D000907:Antibodies, Bacterial; D000992:Antitoxins; D022121:Cholera Vaccines; D014613:Vaccines, Attenuated