Roches Tamiflu Largely Ineffective For This Seasons Flu Bugs
The flu strains that dont respond to Tamiflu didnt make people any sicker than the virus types affected by the drug, according to the study, published online today by the Journal of the American Medical Association today. For now, the U.S. Centers for Disease Control and Prevention recommend that people suffering the miseries of flu use GlaxoSmithKline Plc.s Relenza, or the generic drug rimantadine in combination with Tamiflu.
Flu strikes 5 percent to 15 percent of the population and kills 250,000 to 500,000 people a year worldwide, according to the World Health Organization. The best way to treat the flu is not to get it, and securing a flu shot at the start of the season is the easiest plan, said Alicia Fry, the studys head researcher.
“The vaccine is still the best form of prevention,” said Fry, a researcher for the Atlanta-based CDC. “We also know that these strains are susceptible to other antiviral drugs.”
Several types of flu are currently circulating in the U.S. Only one, H1N1, shows resistance to Tamiflu and the CDC said that flu type is most common now. Last year, only about 12 percent of the strains were resistant to Tamiflu; this year, 98.5 percent of the strains of H1N1 werent affected by the drug.
Alternative Treatment
The strains of the virus arent resistant to Relenza, which is taken through an inhaler, the CDC said in December.
The appearance of flu that doesnt respond to the drug isnt associated with use of Tamiflu, unlike antibiotics that become ineffective when repeated exposure breeds resistance, said Fry. Flu viruses constantly mutate, and researchers had thought that if the germs mutated to be resistant to Tamiflu, they would cause less serious illness.
“What surprised us was how similar it does look to the regular flu virus, in symptoms,” Fry said. “Why it became predominant, we dont know.”
The flu season in the U.S. typically lasts from November through March, according to the CDC. This years flu-shot vaccine, redesigned yearly to protect against three types of flu, is a good match with the circulating strains, Fry said.
Terence Hurley, a spokesman for Roche, didnt return a telephone call today.