Approximately half of those volunteers who received an initial and a booster dose of the highest dosage of the vaccine tested in the trial developed levels of infection-fighting antibodies that current tests predict would neutralize the virus. The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, funded the study, published in the current issue of The New England Journal of Medicine. Preliminary results from this trial were first disclosed late last summer.
"These findings represent an important step forward in the nation's efforts to prepare for the possible emergence of a human pandemic of H5N1 avian influenza," notes NIH Director Elias A. Zerhouni, M.D.
"We are working hard to address the many challenges that remain with regard to the development of an H5N1 vaccine," adds NIAID Director Anthony S. Fauci, M.D. "For example, potentially protective immune responses were seen most frequently at the highest dose of this vaccine. We are investigating other options that may allow us to reduce the dosage--for example, adding an immune booster, or adjuvant, to the vaccine--so we can achieve a more practical immunization strategy." In addition, the U.S. Department of Health and Human Services is pursuing other approaches to an H5N1 vaccine, including vaccines made in cell cultures rather than grown in eggs.
H5N1 avian influenza viruses are of enormous concern to public health officials worldwide. The potential for a human avian flu pandemic looms large, say experts, as daily reports indicate an increasing spread of infection in bird populations in Southeast Asia, Europe, the Middle East and Africa. According to the World Health Organization, as of March 24, 2006, 186 people had been infected with avian flu viruses, and more than half
Source:NIH/National Institute of Allergy and Infectious Diseases