If there is a limited supply of flu vaccine, it should go first to those who have longer to live, doctors argue in today's issue of the journal Science. This is a conclusion that contradicts government recommendations, which say the elderly should be treated before younger people.

If there is a worldwide influenza pandemic, teens and young adults should be first in line to get a vaccine, say two National Institutes of Health bioethicists.

The article was co-authored by Dr. Ezekiel J. Emanuel, the NIH's department of clinical bioethics chairman and a Harvard University-educated doctor. He's also a former Harvard Medical School associate professor and Dana-Farber faculty member.

Health experts fear that a deadly strain of bird flu called H5N1 could mutate into a virus capable of moving rapidly through humans around the world, killing millions.

Older people and those with multiple underlying medical conditions followed by pregnant women, say federal advisers.

The plan is based on the expectation that the elderly are most at risk of dying from the flu. But a 1918 pandemic hit younger people harder, Emanuel said.

"Is it better from an ethical and a moral standpoint to give it to the elderly who have two different illnesses and are at risk of dying?" said Emanual, who at age 48, would go to the end of the line under his plan.

The idea of leaving older people out in the cold is sure to create a big debate. "The most important thing is to talk about the issue and develop a strategy to be prepared", Emanuel said.