title: Evaluation of circulating intestinally committed memory B cells in children vaccinated with attenuated human rotavirus vaccine.
abstract: In a double blind trial, 319 fully immunized children received two doses of either placebo or 10(6.7) focus-forming units of the attenuated RIX4414 human rotavirus (RV) vaccine ("all-in-one" formulation). Plasma RV-specific IgA (RV IgA), stool RV IgA, and circulating total and RV memory B cells (CD19+ IgD+/- CD27+) with an intestinal homing phenotype (alpha4beta7+ CCR9+/-) were measured, after the first and second doses, as potential correlates of protection. After the first and/or second dose, 54% of vaccinees and 13% of placebo recipients had plasma RV IgA. Before vaccination, most (95%) of the children (of both study groups) were breast-fed and had stool RV IgA (68.64%). Coproconversion (4-fold increase) after the first and/or second dose was observed in 32.7% of vaccinees and 17.4% of placebo recipients. No significant difference was seen when comparing the frequencies of any subset of memory B cells between vaccinees and placebo recipients. Statistically significant weak correlations were found between plasma RV IgA titers and coproconversion, and several subsets of memory B cells. The vaccine provided 74.8% protection (95% confidence interval, 30.93-92.62) against any RV gastroenteritis and 100% protection (95% confidence interval, 14.53-100) against severe RV gastroenteritis. When vaccinees and placebo recipients were considered together, a correlation was found between protection from disease and plasma RV IgA measured after dose 2 and RV memory (IgD- CD27+ alpha4beta7+ CCR9+) circulating B cells measured after dose 1. However, the correlation coefficients for both tests were low (<0.2), suggesting that other factors are important in explaining protection from disease.
authors.affiliation: Instituto de Genética Humana, Colombia.
authors.forename: Olga Lucía
authors.initials: OL
authors.lastname: Rojas
authors.forename: Liliana
authors.initials: L
authors.lastname: Caicedo
authors.forename: Carolina
authors.initials: C
authors.lastname: Guzmán
authors.forename: Luz-Stella
authors.initials: LS
authors.lastname: Rodríguez
authors.forename: Javier
authors.initials: J
authors.lastname: Castañeda
authors.forename: Liliana
authors.initials: L
authors.lastname: Uribe
authors.forename: Yohanna
authors.initials: Y
authors.lastname: Andrade
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pinzón
authors.forename: Carlos Fernando
authors.initials: CF
authors.lastname: Narváez
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Lozano
authors.forename: Beatrice
authors.initials: B
authors.lastname: De Vos
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Franco
authors.forename: Juana
authors.initials: J
authors.lastname: Angel
mesh_terms: D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D003105:Colombia; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D007156:Immunologic Memory; D007223:Infant; D008297:Male; D012401:Rotavirus / Q000276:immunology*; D012400:Rotavirus Infections / Q000276:immunology* / Q000517:prevention & control*; D022243:Rotavirus Vaccines / Q000276:immunology*; D014613:Vaccines, Attenuated / Q000276:immunology* / Q000627:therapeutic use
chemical_list: D007070:Immunoglobulin A; C492457:RIX4414 vaccine; D022243:Rotavirus Vaccines; D014613:Vaccines, Attenuated