Saturday, October 24, 2009

H1N1 - things new to me

I have an average physicians knowledge of H1N1, so most of what I read is uninteresting. This MinnPost article by a local physician, however, had some real gems. Osterholm is a national expert on pandemics living in MN. His predictive record is imperfect, but he has some interesting observations (emphases mine) ...
MinnPost - Tapping Minnesota’s top H1N1 expert: Michael Osterholm

... Osterholm chairs a National Institutes of Health (NIH)-sponsored panel that tracks emerging influenza infections. This year's meeting included a group of virologists and influenza experts that Osterholm considers to be the best in the world. "And every one of them said without a question that if this H1N1 acquires a certain PB2 gene, we're in big trouble," Osterholm recalled. "Well, it did it [acquire the PB2 gene] in the Friesian islands off of the Netherlands this August, and we didn't see that. Everyone was holding their breath, but at least, so far, nothing has happened with that. And so we don't understand in many instances what components of the mutt are really critical, which ones are important and which ones don't make any difference."

... I have been concerned from the beginning about over-promising and under-delivering on this issue. Just knowing this vaccine and what it takes, when they put the 140 million-dose estimate out that would be here in mid-October, I just knew that that was going to be a great overreach....

... I find it remarkable that we have as much as we do as early as we do, given the timeline..."

Long before the arrival of the novel H1N1 virus, Osterholm and other infectious disease specialists were lamenting our country's antiquated vaccine production system, which he points out relies on 1950s technology that's slow and unreliable. And even the way in which influenza vaccines work is a little bit murky.

"On Monday, I'm giving the keynote address to the NIH vaccine research meeting," he said. "I'm actually using H1N1 to highlight the many problems we have today with the vaccine industry. It's a simple as, 'You know, we don't have a clue what protects you in a flu vaccine.' So we measure hemagglutinin [the 'H' in H1N1] using outdated measures for antigen [a molecule on the surface of a virus that our immune system uses to key in on it], but we don't really know."

"When the CDC did their sero-survey looking for hemagglutinin antibody to novel H1N1 in the elderly, they found about 30 percent of them having pretty good titers to the H1 N1 virus," Osterholm recalled. "But the bottom line is, the protection we're seeing in the 65 and older age population far exceeds 30 percent, and the point of it is that there is probably a huge part of cellular immunity that's tied to protection with the flu vaccine, and that's something we don't even understand....
... The one thing I do feel pretty good about is the safety issue. It's not because we know it from this vaccine, but from the time-tested seasonal flu vaccines we've used over the last 30 years."

So the vaccine will get here when it gets here, but do you have a sense of when the peak of infections will be?

"You know, I don't. As I said at the flu summit six weeks ago, I thought that by mid-October we'd be seeing what I call 'peak activity,' which is what we're seeing right now. That's how I thought it would build. What I don't know is how long this is going to last. Is it basically going to go into retreat for a while and then come back again in, say, December or January? We're burning through a lot of central people right now, meaning the rate of new infections is growing at such a rate that I think that we're not going to have that many [unexposed] people left in November, December or January to get a second wave...

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