The young should be prioritised for vaccination over the elderly, ill and disabled in the event of a flu pandemic, US researchers suggest.
Vaccines are likely to be in short supply
The team says with stocks of bird flu vaccine likely to be limited, society faces a "fundamental ethical dilemma" about who should get the jabs first.
Health staff and the old are set to be priority groups.
But the report in Science argues the young have a right to live through all life's stages and should be a priority.
It says the primary issues to "decrease health impacts" including illness and death.
A second goal was to limit impacts on society.
But the researchers, led by Ezekiel Emanuel of the National Institutes of Health, say an alternative ethical framework should be considered.
Vaccines protecting against any new form of the H5N1 strain of bird flu which can pass easily between humans will be limited in supply, they say.
And it is likely that no more than 10% of the US population will be inoculated against the disease in the first year.
Experience of the three major flu pandemics have given mixed messages about who is most likely to be at risk, with differing experiences in each.
The report says: "With limited vaccine supply, uncertainty over who will be at highest risk of infection and complications, and questions about which historic pandemic experience is most applicable, society faces a fundamental ethical dilemma. Who should get the vaccine first?"
They say a range of principles have guided rationing of medicines or vaccines in the past including "save the most likely to recover" and "save the most lives".
The team say they disagree with the latter, which they argue underlines the policy of giving vaccines to those at highest risk before the well and young.
Instead they argue that each person having an opportunity to live through all stages of life is more appropriate.
They continue: "There is great value to being able to pass through each life stage - to be a child, a young adult and to then develop a career and family, and to grow old."
They add: "Death seems more tragic when a child or young adult dies than an elderly person - not because the lives of older people are less valuable but because the younger person has not had the opportunity to live and develop through all stages of life."
The team concludes that a global pandemic would make all the issues about sharing vaccines and working with other countries even more pertinent.
A spokeswoman for the Department of Health said it had not drawn up priorities for vaccination yet but that its decisions would be informed by emerging evidence.
They would also be guided by World Health Organization principles aimed at protecting healthcare workers most at risk and those needed to keep essential services running.
They would also aim to prevent serious illness in the most vulnerable groups, reduce the spread of infection by immunising those in closed communities and children.
A spokeswoman added: "The UK National Influenza Pandemic Committee (UKNIPC) will make final decisions regarding priority groups and priority order."