title: Mucosal immune response to trivalent live attenuated intranasal influenza vaccine in children.
abstract: Intranasal trivalent, cold-adapted, live attenuated influenza vaccine (CAIV-T) is a promising alternative to inactivated vaccine for protection against influenza in children. However, correlates of immunity are not well defined. To determine the mucosal immune response to CAIV-T, 19 children ages 15-55 months were randomized to receive two doses of CAIV-T or placebo. Influenza-specific IgA to the haemagglutinin of each of three contemporary strains was measured in nasal washes collected pre- and postvaccination using a kinetic enzyme-linked immunosorbent assay. After two doses of study drug, 62, 69 and 85% of CAIV-T recipients demonstrated a mucosal IgA response to influenza A/H1N1, A/H3N2, and B strains respectively; in comparison, 33, 0 and 17% of placebo recipients demonstrated an IgA response to the same strains (p = 0.35, 0.01 and 0.01). Overall, seropositive vaccinees were 4.5 times more likely to develop a mucosal immune response than an HAI response (p = 0.015). Two doses of CAIV-T induce a mucosal IgA response to all three influenza vaccine antigens in the majority of children. In addition, a mucosal antibody response may be the only indication of a vaccine take in a seropositive child.
authors.affiliation: Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA. thomas.boyce@mcmail.vanderbilt.edu
authors.forename: T G
authors.initials: TG
authors.lastname: Boyce
authors.forename: W C
authors.initials: WC
authors.lastname: Gruber
authors.forename: S D
authors.initials: SD
authors.lastname: Coleman-Dockery
authors.forename: E C
authors.initials: EC
authors.lastname: Sannella
authors.forename: G W
authors.initials: GW
authors.lastname: Reed
authors.forename: M
authors.initials: M
authors.lastname: Wolff
authors.forename: P F
authors.initials: PF
authors.lastname: Wright
mesh_terms: D000281:Administration, Intranasal; D000914:Antibodies, Viral / Q000032:analysis*; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D018928:Immunity, Mucosal; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D007223:Infant; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D009975:Orthomyxoviridae / Q000276:immunology*; D012680:Sensitivity and Specificity; D014613:Vaccines, Attenuated / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D007071:Immunoglobulin A, Secretory; D007252:Influenza Vaccines; D014613:Vaccines, Attenuated