Intradermal flu vax promising

INTRADERMAL administration of the influenza vaccine in the elderly may produce superior immunogenicity compared with intramuscular injection, an Australian GP trial shows.

A phase II study, using a new intradermal micro-injection needle with pre-filled syringe, suggested this could be the method of choice in the future, investigator Professor Robert Booy said.

“With this system you can get reliable injection of product into the skin, and because the skin has highly reactive dendritic cells... they cause the production of higher levels of antibody than an injection given under the skin,” he said.

The study, sponsored by Sanofi Pasteur, involved 1100 volunteers aged 60-85 years randomised to the trial vaccine or Vaxigrip. Antibody titres for each strain were superior in those receiving the intradermal vaccine.

Delivery was simpler and potentially better tolerated, with the main adverse reactions being increased erythema, but not pain.

J Infect Dis 2008; 198:650-58.