More cases of H1N1 resistant to Roche's Tamiflu antiviral have cropped up. According to the World Health Organization, China and Singapore have each found Tamiflu-resistant viruses. And Charles Penn, a WHO scientist, told the Canadian Press that WHO has been formally alerted to a small number of other resistant pandemic viruses.
"It's a small number. It certainly doesn't change the scale of what we're seeing," Penn said, declining to specify where the H1N1 resistance was found or how many resistant viruses it has found overall. The Canadian Press reports that Japan has found three cases of resistance, with Canada, Denmark, Hong Kong and Singapore each discovering one.
The big question: Whether the resistant virus found in China has been checked to see if the pandemic H1N1 virus might have swapped genes with seasonal H1N1. As you know, last year Tamiflu was declared all but useless for the dominant strain of seasonal flu; if the pandemic flu did pick up those resistance genes, it would render government stockpiles of the drug much less effective to treat severe cases or slow spread of the virus. And it might steer new business to GlaxoSmithKline's Relenza drug.
So far, there's no evidence of that sort of gene reassortment. And there's no evidence that the resistant cases are spreading from person to person.
- read the Canadian Press piece