A self-administered patch containing tiny microneedles may effectively deliver influenza virus-like particles through the skin and protect against potentially pandemic flu viruses such as H5N1. Researchers from the U.S. and abroad report their findings in the September 2010 issue of the journal Clinical Vaccine and Immunology.
In the United States, seasonal flu epidemics often result in over 200,000 hospitalizations and 36,000 deaths each year. New pandemic flu strains continue to emerge, such as the 2009 H1N1 virus that resulted in the first pandemic influenza outbreak in the 21st century. Conventional vaccination programs require a painful injection administered by medical personnel and can take months to develop, emphasizing the need for vaccines that can be rapidly produced at low cost and distributed within weeks.
Influenza virus-like particles (VLPs) are potentially promising vaccine candidates as they are non-infectious and have been shown to induce long-lasting immunity against pandemic influenza viruses. An abundance of dermal dendritic cells, important members of the skins' immune system, make the skin an appealing route for vaccine delivery.
In the study researchers vaccinated mice with microneedle patches containing influenza H5 VLPs derived from the H5N1 virus and found the resulting protective immunity to be equal to or higher than that induced from intramuscular inoculation. Significantly, human skin cells also responded to the influenza VLP vaccine delivered by the microneedle patch.
"Microneedle vaccination in the skin with H5 VLPs represents a promising approach for a self-administered vaccine against viruses with pandemic potential," say the researchers.
(J.M. Song, Y.C. Kim, A.S. Lipatov, M. Pearton, C.T. Davis, D.G. Yoo, K.M. Park, L.M. Chen, F.S. Quan, J.C. Birchall, R.O. Donis, M.R. Prausnitz, R.W. Compans, S.M. Kang. 2010. Microneedle delivery of H5N1 influenza virus-like particles to the skin induces long-lasting B- and T-cell responses in mice. Clinical and Vaccine Immunology, 17. 9: 1381-1389.)