"Certain military personnel like deployed forces would get vaccinated before certain other military personnel," HHS science adviser William Raub said in a telephone interview.

Virtually all health experts agree that the world is overdue for a pandemic of some sort of influenza.

No one can predict when one might come, how bad it would be or which strain of influenza virus may be responsible. But the H5N1 bird flu virus that has infected 331 people since 2003, killing 203 of them, is the current chief candidate.