Bird Flu - Limited Human Immunity?

Interesting if true: ABC News reports on a study by flu researchers that indicates that humans may have some limited natural immunity to the H5N1 bird flu virus:

In the H5N1 bird flu, it's the H5 part that is most foreign to humans. The N1 part is more common in typical human flu viruses.

[Dr. Richard Webby of St. Jude's Children's Research Hospital] and his colleagues investigated this theory in a new study published this week in PLOS Medicine.

In mice, exposure to an N1-containing virus reduced the death rate from H5N1 bird flu by half.

Preliminary blood work on humans also suggests that yearly flu shots with N1 may offer some weak protection against H5N1 bird flu.

The exact amount of protection a person would have is unknown. "It's not going to prevent infection," Webby said. "But it might reduce the more severe parts of the disease."

Even if these findings are verified by further studies, this is not a magic bullet. Still, generally speaking, multiple layers of various interventions - i.e., concentric circles of protection - tend to provide a more workable, cost-effective solution than a single magic bullet, for all types of threats.

Let's hope that the good-old annual flu shot turns out to be an effective initial layer of intervention - even if it's only very limited. It's hard to imagine a simpler or more easily understood intervention than the annual flu shot.

And one more question, just thinking aloud: I wonder if anyone could do - or is doing - an epidemiological study of flu vaccination in the populations of humans (mostly in Asia) who have already been affected by bird flu. Are seasonal flu vaccinations administered in Indonesia, Thailand, Vietnam, etc.? If so, have they had any effect on the mortality rate among the affected populations so far?