Apr 28, 2010
Two companies say unconventional flu vaccines looked good in trials
Two companiesVaxInnate Corp. in Cranford, N.J., and BiondVax Pharmaceuticals, an Israeli firmhave reported good results in clinical trials of their experimental influenza vaccines involving new technologies. Yesterday at a vaccine research conference in Bethesda, Md., VaxInnate reported preliminary phase 2 trial data for its VAX 125 seasonal flu vaccine. Tested at six different doses in 120 elderly people, the vaccine was well tolerated and yielded seroprotection (a minimum antihemagglutinin (HA) titer of 1:40) in 84% of the volunteers, the company reported. The vaccine, intended for the elderly, links HA to flagellin, a bacterial protein that interacts with the immune system's toll-like receptors. Today, BiondVax reported that its experimental "universal" flu vaccine, called Multimeric-001, performed well in a phase 1/2 clinical trial in 60 people aged 55 to 75 years, as it had previously in a phase 1/2 trial in younger adults. It was well tolerated, and it generated significant increases in antibodies and in the secretion of interferon gamma and interleukin-2, signaling activation of both the humoral and cellular immune systems, the company said. The firm did not release details but said it would report its results at the BIO International Convention in Chicago on May 5.
Apr 27 VaxInnate release
Apr 28 BiondVax release
Experts discuss doubts about flu vaccine benefits for elderly
Editor's note: This item was revised Apr 30 to clarify comments attributed to Dr. Ed Belongia.
Flu experts quoted in a Minnesota Public Radio (MPR) report yesterday agreed there is growing evidence that flu vaccines don't protect elderly people from flu-related death, but they didn't entirely agree about how much this should be publicized. Michael T. Osterholm, PhD, MPH, director of the University of Minnesota Center for Infectious Disease Research and Policy, publisher of CIDRAP News, told a national conference on vaccine research yesterday that it's time to be more open about the vaccine's lack of effectiveness in older people, the report said. Flu vaccines don't work as well in older people as in younger because the aging immune system responds less vigorously, the story noted. It said the vaccine may offer some protection in healthy older people, but evidence suggests it does not protect the frail elderly. Kris Ehresmann, immunization director for the Minnesota Department of Health, said she welcomes the findings but worries that if they are publicized, people will think there is no reason to get a flu vaccination. Dr. Ed Belongia of the Marshfield Clinic in Marshfield, Wis., who has studied flu vaccine effectiveness, said it's clear that the vaccine has some effect in older people but doesn't work as well as once thought. Osterholm said he initially was reluctant to accept the evidence that flu vaccines don't save elderly people's lives but now finds it incontrovertible. He added that new vaccines that work better in the elderly are needed. As noted in the story, a high-dose vaccine intended for the elderly was licensed by the Food and Drug Administration this year.
Apr 27 MPR report
Study sheds light on innate immune response to flu
A study published today in Nature details the key role that the protein Mx, short for myxovirus resistance, plays in the body's innate immune response to influenza and other first-time viral invaders. In the article, German researchers discuss the structure of the Mx protein and its antiviral effect. Normally the Mx protein is not present in the cell being invaded by a virus, but after infection it can be produced in large amounts, according to a news release today. Mx production is triggered by the signaling protein interferon, which is excreted by infected cells and alerts the body to the virus's presence. Once production starts, Mx does not develop its full power until its individual molecules have joined to form a ring-like structure. A central element of the Mx ring is known as the stalk, and this study sheds light on the structure of the stalk. This knowledge allows scientists to conduct tests to permit predictions concerning the antiviral mode of action of this protein, according to today's release. The study indicates that the stalk structure of Mx serves as a kind of clamp that restrains and deactivates important components of the flu virus in infected cells. The findings may help in developing new antiviral drugs.
Apr 28 Nature abstract
Apr 28 Helmholtz Association of German Research Centres press release