10 March 2008

Cautionary tale: Unintended consequences, ripple effects

New story by me, up at the news website of the Center for Infectious Disease Research and Policy, where I am a contributing writer. It's on flu, not MRSA, but it contains lessons that apply to MRSA too.

Gist: This flu season turned out unexpectedly badly, with physicians across the country saying offices and ERs are overwhelmed with very sick patients. In ERs in particular, the dominos fall like this: More patients than usual come in for help; with some of them seriously sick, other patients get pushed further back in the triage queue; while the seriously sick wait in the ER for hospital admission, other patients back up in the waiting room; diversion (turning ambulances away) is called to relieve some of the pressure; and patients are taken instead to another ER, where the process begins again.

The irony here is that flu is an at least partially preventable disease: Under normal circumstances, get a flu shot, sharply reduce your chance of getting the flu. However, this year the flu vaccine and the circulating flu strains don't match well, and many people who stepped up and got the shot still developed flu. And why did the shot not match? It was partly a failure of luck — flu's perpetual genetic drift is unpredictable — but it was also a failure of infrastructure: Federal health planners knew a year ago that one strain was drifting, but that virus didn't grow well enough under lab conditions to get an isolate to vaccine manufacturers in time for it to be included in last fall's vaccine. (See Dr. Nancy Cox's comments in this CDC press briefing; the FDA discussions she refers to are archived here.)

And why did it have to be given to the manufacturers a year ago? Because it still takes 6 months to make commercial quantities of flu vaccine, using a technology that is essentially 50 years old. This despite either 10 years or 32 years of concern over the possibility of a flu pandemic (depending on whether you start counting from the appearance of avian flu H5N1 or the aftermath of the 1976 swine flu).

And why is any of this of concern for MRSA? Because many researchers and clinicians say that the only way to combat MRSA effectively is with a vaccine. Improving flu vaccination has been top of the public health wish-list, and a target of significant government funding, for years now, and yet it is still a disappointing mess. What chance for a lower-profile MRSA vaccine?

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