H5N1
Researchers from Hungary and the United Kingdom have developed a single-dose H5N1 influenza vaccine that induces a protective level of immunity against infection in healthy adult and elderly volunteers.
They report their findings in the February 2010 issue of the Journal of Virology.
New cases of human H5N1 infection continue to emerge worldwide resulting in severe illness and high fatality rates. A variety of candidate vaccines are being tested, but most require two-dose regimens to be effective.
This new vaccine is the first single-dose regimen to be tested in elderly subjects and it fulfills all European Union and U.S. licensing criteria offering a promising influenza A virus vaccine candidate.
In the study researchers developed a whole-virion, inactivated, adjuvanted H5N1 vaccine and tested its safety and efficacy in healthy adult and elderly volunteers. Subjects were randomly assigned to receive one or two doses of 3.5 micrograms of the vaccine or one dose of 6 or 12 micrograms of the vaccine.
While antibody responses were observed in all the subjects, single doses of 6 micrograms or more fulfilled the European Union and U.S. licensing criteria.
"We found that the present vaccine is safe and immunogenic in healthy adult and elderly subjects and requires low doses and, unlike any other H5N1 vaccines, only one injection to trigger immune responses which comply with licensing criteria," the researchers said.
