MADISON The specter of a drug-resistant form of the deadly H5N1 avian influenza is a nightmare to keep public health officials awake at night.
Now, however, a study published this week (Dec. 21) in the Proceedings of the National Academy of Sciences (PNAS) suggests that a new compound, one on the threshold of final testing in humans, may be more potent and safer for treating "bird flu" than the antiviral drug best known by the trade name Tamiflu.
Known as T-705, the compound even works several days after infection, according to Yoshihiro Kawaoka, a University of Wisconsin-Madison virologist and the senior author of the new PNAS study.
"H5N1 virus is so pathogenic even Tamiflu doesn't protect all the infected animals," explains Kawaoka, a professor of pathobiological sciences at the UW-Madison School of Veterinary Medicine and a world authority on influenza. "This compound works much better, even three days after infection."
The Wisconsin research was conducted in mice and demonstrated that the compound was effective and safe against H5N1 virus, the highly pathogenic bird flu virus, which some scientists fear could spark a global epidemic of deadly influenza. The compound is also effective against seasonal flu and more worrisome varieties such as the H1N1 virus, and has already been tested against circulating seasonal influenza in humans in Japan where it is on the brink of Phase III clinical trials in people.
The prospect of a new front-line drug for influenza, in particular highly pathogenic strains such as H5N1 virus, is important as there are few drugs capable of checking the shifty influenza virus. The new study showing the efficacy and safety of T-705 assumes more importance as instances of Tamiflu-resistant strains of H5N1 virus have recently been reported, raising concerns about the ability of current antiviral drugs to blunt a pandemic of deadly avian flu.
Antiviral drugs are viewed as a readily availab
|Contact: Yoshihiro Kawaoka|
University of Wisconsin-Madison