The researchers have high hopes that their work will lead to more effective vaccines. That could have special implications for the elderly.
"Elderly individuals don't respond well to exposure to a vaccine, so they don't generate a good immune response," says Padgett. Maybe, he adds, their cells just don't remember the vaccine, so they are unable to recognize the virus, leaving them with their defenses down.
The next step is to unravel the mechanisms and the physiology at work here. Then, perhaps vaccines can be modified so that they can stimulate the cellular memory.
Of course, there's still some question about whether humans will react the same as mice, but there's reason to be optimistic.
"The mouse immune response is quite comparable to that of the human," Padgett says. "that's why we chose it."
However, none of the researchers thinks it's a good idea for us to expose ourselves to a little stress so we can avoid the flu.
"I wouldn't do that at all," Padgett says. "I try to avoid stress at all costs."
Lee Dye's column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.