Comparison of 2 different regimens for reactogenicity, safety, and immunogenicity of the live attenuated oral rotavirus vaccine RIX4414 coadministered with oral polio vaccine in South African infants.
BACKGROUND
A phase II, randomized, double-blind, placebo-controlled study was conducted in South Africa during 2003-2004 to evaluate the safety, reactogenicity, and immunogenicity of 2 regimens of the live attenuated oral human rotavirus vaccine RIX4414 when coadministered with the Expanded Program on Immunization childhood vaccines, including oral polio vaccine.


METHODS
Healthy infants were randomized (2:2:1) to receive either 2 doses of RIX4414 (n = 190; at 10 and 14 weeks, with placebo at 6 weeks), 3 doses of RIX4414 (n = 189; at 6, 10, and 14 weeks), or 3 doses of placebo (n = 96), all with concomitant routine vaccinations. The antirotavirus IgA seroconversion rate was assessed using enzyme-linked immunosorbent assay at 2 months after the last dose of RIX4414 or placebo. Antipolio types 1, 2, and 3 antibodies were measured using a virus neutralization assay. Solicited symptoms were recorded for 15 days after each dose.


RESULTS
The antirotavirus IgA seroconversion rates were similar in the RIX4414 2- and 3-dose groups (44.3% and 44.4%, respectively; P = .544, by 1-sided Fisher exact test) and antirotavirus IgA geometric mean concentrations were also comparable. Seroprotection rates for antipolio types 1, 2, and 3 antibodies were high (93%-100%) and were not significantly different among groups. Solicited symptoms reported within 15 days after vaccination were similar in all groups.


CONCLUSIONS
The immune seroconversion response to the RIX4414 vaccine with 3 doses was not superior to the 2-dose regimen. There was no interference by either regimen with antibody response to oral polio vaccine, and RIX4414 was well tolerated when given with routine vaccinations.
Steele
A D
AD
MRC Diarrhoeal Pathogens Research Unit, University of Limpopo, Pretoria, Republic of South Africa. dsteele@path.org
Reynders
J
J
Scholtz
F
F
Bos
P
P
de Beer
M C
MC
Tumbo
J
J
Van der Merwe
C F
CF
Delem
A
A
De Vos
B
B
D000284:Administration, Oral; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000097:blood; D004311:Double-Blind Method; D004347:Drug Interactions; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007070:Immunoglobulin A / Q000097:blood; D007223:Infant; D008297:Male; D011051:Poliomyelitis / Q000453:epidemiology / Q000517:prevention & control*; D011055:Poliovirus Vaccine, Oral / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D012400:Rotavirus Infections / Q000453:epidemiology / Q000517:prevention & control*; D022243:Rotavirus Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D013019:South Africa / Q000453:epidemiology; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
D000914:Antibodies, Viral; D007070:Immunoglobulin A; D011055:Poliovirus Vaccine, Oral; D022243:Rotavirus Vaccines; D014613:Vaccines, Attenuated