title: A randomized trial of one versus two doses of influenza vaccine after allogeneic transplantation.
abstract: Influenza infection after allogeneic hematopoietic cell transplantation (allo-HCT) can result in severe complications. The effectiveness of the annual vaccine depends on age, immune competence, and the antigenic potential of the 3 strains included. We hypothesized that a second vaccine dose, the standard of care for vaccine-naïve children, might improve post hematopoietic cell transplantation (HCT) immune responses. Patients >60 days post-HCT were randomized to receive either 1 (n = 33) or 2 (n = 32) influenza vaccine doses separated by 1 month. The primary endpoint was whether 2 vaccinations induced superior immunity; however, we found no difference. Secondary endpoints were to identify variables associated with responses. Both hemagglutination inhibition (HI; P < .005) and ELISpot responses (P = .03) were greater for patients vaccinated ≥ 1 year posttransplantation. Umbilical cord blood (UCB) recipients showed less IFN-γ responses (P < .001). Interestingly, there was a positive correlation between the total number of CD19(+) cells before vaccination and seroconversion (P = .01) and an inverse correlation for IFN-γ responses (P = .05). Variables not associated with vaccine responses included prevaccine CD4(+) cell counts (total, naïve, or memory), steroid usage at vaccination, age, or conditioning intensity. Time from transplantation to vaccination and absolute CD19(+) cell counts were the strongest predictors of vaccine responses. Methods to improve influenza vaccine responses after allo-HCT are needed.
authors.affiliation: Division of Hematology/Oncology and Blood and Marrow Transplantation, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Karras
authors.forename: Matthew
authors.initials: M
authors.lastname: Weeres
authors.forename: Wendy
authors.initials: W
authors.lastname: Sessions
authors.forename: Xiyan
authors.initials: X
authors.lastname: Xu
authors.forename: Todd
authors.initials: T
authors.lastname: Defor
authors.forename: Jo-Anne H
authors.initials: JA
authors.lastname: Young
authors.forename: Heather
authors.initials: H
authors.lastname: Stefanski
authors.forename: Claudio
authors.initials: C
authors.lastname: Brunstein
authors.forename: Sarah
authors.initials: S
authors.lastname: Cooley
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Miller
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Blazar
authors.forename: John E
authors.initials: JE
authors.lastname: Wagner
authors.forename: Michael R
authors.initials: MR
authors.lastname: Verneris
mesh_terms: D000293:Adolescent; D000328:Adult; D018941:Antigens, CD19 / Q000097:blood / Q000276:immunology; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D058501:Enzyme-Linked Immunospot Assay; D005260:Female; D005500:Follow-Up Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology; D007371:Interferon-gamma / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014184:Transplantation, Homologous
chemical_list: D018941:Antigens, CD19; C573415:IFNG protein, human; D007252:Influenza Vaccines; D007371:Interferon-gamma