Superior immunogenicity profile of the new intradermal influenza vaccine compared to the standard subcutaneous vaccine in subjects 65 years and older: A randomized controlled phase III study.

Background: Although the elderly are at high risk for influenza, the immunogenicity in the elderly is lower than that in younger adults. We developed the new type of seasonal influenza vaccine with the novel intradermal (ID) injection system. In the previous exploratory phase I/II study of the ID vaccine with a dose of 15 μg HA per strain showed the superior immunogenicity profile to that of the standard subcutaneous (SC) injection vaccine in subjects aged 20 years and older.

Immunogenicity and safety of the new intradermal influenza vaccine in adults and elderly: A randomized phase 1/2 clinical trial.

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.