Where the flu's at

In his morning news roundup at Slate today, Daniel Politi hits what seems to me -- this morning, anyway -- about the right tone, which is that the events of the last 24 hours are encouraging. (Though I wouldn't throw out those flu masks just yet.)

The New York Times points out that while the WHO urged calm, Chan "at times spoke as if a pandemic had already begun." Speaking to reporters, Chan said: "The biggest question right now is this: How severe will the pandemic be?" The Los Angeles Times is by far the most optimistic and points out that experts seem to be coming to the conclusion that, in its current form, the H1N1 virus "isn't shaping up to be as fatal as the strains that caused some previous pandemics." Although the virus does appear to spread easily, it doesn't seem like its mortality rate will get anywhere close to the typical flu season that kills 36,000 people in the United States. The Wall Street Journal points out that some Mexican doctors believe many more people had the virus than the official numbers indicate, "suggesting it could turn out to be a relatively mild pandemic." [This was the possibility I explored in my Slate article on Monday.] But, of course, the flu virus is very unpredictable, and we're still at the early stage, so it could just as easily mutate and become much deadlier.

As it stands now, swine flu "may not even do as much damage as the run-of-the-mill flu outbreaks that occur each winter without much fanfare," notes the LAT. At first many were worried about what appeared to be striking similarities between the current virus and the 1918 flu that killed approximately 50 million people. But upon closer analysis, experts are feeling optimistic about what they are seeing. "There are certain characteristics, molecular signatures, which this virus lacks," an influenza expert tells the LAT. There are suggestions that those who were exposed to the 1957 flu pandemic may have some automatic immunity from the current virus, which might explain why swine flu appears to be particularly deadly for young people. And, as has been emphasized before, experts cautioned against inferring that the increasing number of cases means the virus is spreading particularly quickly. "You don't ever find anything that you don't look for," a molecular virologist said.

I'd balance this by pointing out that many virologists seem rather flummoxed by this virus, so it's possible the more optimistic assessments could be overlooking something novel. It's possible, in short, that while they're not seeing danger signs they know from prior viruses, they're also unable to see -- because they've not occurred yet -- danger signs in this one. Plus the virus itself can (and probably will) change.

Still, these suggestions of low virulence are what you'd hope to see.