title: Immunogenicity and safety of the new intradermal influenza vaccine in adults and elderly: A randomized phase 1/2 clinical trial.
abstract: BACKGROUND
  Recent clinical evidence indicates that an intradermal (ID) delivery of vaccines confers superior immunogenicity as compared to a standard intramuscular or subcutaneous (SC) delivery.
  
  
  METHODS
  In this exploratory study, 600 healthy adults were randomized to 6 study groups with subgroups of young adults (20-64 years old) and older adults (65 years and older). The subjects were either injected by a novel ID injection system with a single dose of 6, 9, or 15 μg HA or two doses (21 days apart) of 15 μg HA per strain or injected by an SC injection method with a single or two doses (21 days apart) of 15 μg HA per strain. Immunogenicity was assessed using hemagglutination inhibition (HAI) titer and microneutralization titer on Days 0, 10, 21, and 42. Solicited and unsolicited adverse events were recorded for 7 and 21 days post-vaccination, respectively.
  
  
  RESULTS
  In both young adults and older adults groups, the geometric titer (GMT) ratios of HAI in the ID 15 μg HA group were higher than those in the SC 15 μg HA group on both Day 10 and Day 21, while those in the ID 6 and ID 9 μg HA groups were comparable with those in the SC 15 μg HA group. The kinetics of GMTs of HAI suggested that the ID vaccine has the potential to induce the prompt immune response, which is rather hampered in older adults as seen in the SC vaccine groups. The injection-site AEs were generally mild and transient, and did not occur in a dose or dosage-dependent manner.
  
  
  CONCLUSIONS
  The results of this study clearly suggest that the immunologic profile of the ID vaccine is better than that of the SC vaccine, while the safety profile of the ID vaccine is similar to that of the SC vaccine. In this exploratory study with almost 100 subjects per each group, single or two-dose administration of the ID vaccine containing 15 μg HA was suggested to be an appropriate regimen in order to prevent influenza and to reduce the associated disease burden.
  
  
  BACKGROUND
  JAPIC Clinical Trials Information (JapicCTI-132096).
authors.affiliation: Daiichi Sankyo Co. Ltd, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Arakane
authors.affiliation: Daiichi Sankyo Co. Ltd, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Nakatani
authors.affiliation: Daiichi Sankyo Co. Ltd, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Fujisaki
authors.affiliation: Daiichi Sankyo Co. Ltd, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Takahama
authors.affiliation: Daiichi Sankyo Co. Ltd, Japan.
authors.forename: Katsuyasu
authors.initials: K
authors.lastname: Ishida
authors.affiliation: Daiichi Sankyo Co. Ltd, Japan.
authors.forename: Michiharu
authors.initials: M
authors.lastname: Yoshiike
authors.affiliation: Kitasato Institute for Life Sciences, Laboratory of Viral Infection, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nakayama
authors.affiliation: Daiichi Sankyo Co. Ltd, Japan. Electronic address: Takeshita.fumihiko.aw@daiichisankyo.co.jp.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Takeshita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D064420:Drug-Related Side Effects and Adverse Reactions / Q000473:pathology; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D007271:Injections, Intradermal; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines