title: Homologous boosting with adenoviral serotype 5 HIV vaccine (rAd5) vector can boost antibody responses despite preexisting vector-specific immunity in a randomized phase I clinical trial.
abstract: BACKGROUND
  Needle-free delivery improves the immunogenicity of DNA vaccines but is also associated with more local reactogenicity. Here we report the first comparison of Biojector and needle administration of a candidate rAd5 HIV vaccine.
  
  
  METHODS
  Thirty-one adults, 18-55 years, 20 naive and 11 prior rAd5 vaccine recipients were randomized to receive single rAd5 vaccine via needle or Biojector IM injection at 1010 PU in a Phase I open label clinical trial. Solicited reactogenicity was collected for 5 days; clinical safety and immunogenicity follow-up was continued for 24 weeks.
  
  
  RESULTS
  Overall, injections by either method were well tolerated. There were no serious adverse events. Frequency of any local reactogenicity was 16/16 (100%) for Biojector compared to 11/15 (73%) for needle injections. There was no difference in HIV Env-specific antibody response between Biojector and needle delivery. Env-specific antibody responses were more than 10-fold higher in subjects receiving a booster dose of rAd5 vaccine than after a single dose delivered by either method regardless of interval between prime and boost.
  
  
  CONCLUSIONS
  Biojector delivery did not improve antibody responses to the rAd5 vaccine compared to needle administration. Homologous boosting with rAd5 gene-based vectors can boost insert-specific antibody responses despite pre-existing vector-specific immunity.
  
  
  BACKGROUND
  Clinicaltrials.gov NCT00709605 NCT00709605.
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Uzma N
authors.initials: UN
authors.lastname: Sarwar
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Laura
authors.initials: L
authors.lastname: Novik
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Enama
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Plummer
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Koup
authors.affiliation: Biostatistics Research Branch, Division of Clinical Research, NIAID, NIH, Bethesda, MD, United States of America.
authors.forename: Martha C
authors.initials: MC
authors.lastname: Nason
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Bailer
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Adrian B
authors.initials: AB
authors.lastname: McDermott
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Mario
authors.initials: M
authors.lastname: Roederer
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: John R
authors.initials: JR
authors.lastname: Mascola
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Julie E
authors.initials: JE
authors.lastname: Ledgerwood
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Barney S
authors.initials: BS
authors.lastname: Graham
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D000256:Adenoviridae / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D004797:Enzyme-Linked Immunosorbent Assay; D005822:Genetic Vectors; D015483:HIV Antibodies / Q000096:biosynthesis*; D006801:Humans; D008875:Middle Aged; D055815:Young Adult
chemical_list: D016915:AIDS Vaccines; D015483:HIV Antibodies