A phase I evaluation of inactivated influenza A/H5N1 vaccine administered by the intradermal or the intramuscular route

Vaccine. 2010 Apr 9;28(17):3025-9. doi: 10.1016/j.vaccine.2009.10.152. Epub 2009 Nov 18.


In a phase I clinical trial, one hundred healthy young adults were randomized to receive two doses 28 days apart of an inactivated, subvirion vaccine containing 15 or 45microg of influenza A/H5N1 hemagglutinin (HA) by the intramuscular (IM) route, or 3 or 9microg of H5 HA by the intradermal(ID) route. Seventy-seven subjects received a third dose. All regimens were safe and well tolerated. Antibody responses after two or three doses were low (<or=20% or <or=38%, respectively) and similar in groups given 3 or 9microg ID or 15microg IM, and were significantly lower than those given 45microg IM. Higher dosages of H5 HA and/or inclusion of adjuvant will be required to enhance immunogenicity by the ID route.

Publication types

  • Clinical Trial, Phase I
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antibodies, Viral / blood
  • Female
  • Humans
  • Immunization, Secondary
  • Influenza A Virus, H5N1 Subtype / immunology*
  • Influenza Vaccines / administration & dosage
  • Influenza Vaccines / adverse effects
  • Influenza Vaccines / immunology*
  • Influenza, Human / prevention & control*
  • Injections, Intradermal
  • Injections, Intramuscular
  • Male
  • Vaccines, Inactivated / administration & dosage
  • Vaccines, Inactivated / adverse effects
  • Vaccines, Inactivated / immunology
  • Young Adult


  • Antibodies, Viral
  • Influenza Vaccines
  • Vaccines, Inactivated