The current epidemic strain evolved at the beginning of the 20th century - probably between 1908 and 1943.
Get yourself (or family members age 6 months and older) vaccinated against current strains of influenza, if possible.
If the swine flu mutates, scientists aren't sure how effective a vaccine made now from the current strain will remain.
This current strain of H5N1 is unusual in being deadly to so many species.
Despite this origin, the current strain is a human-to-human transmitted virus, requiring no contact with swine.
Court administrators said the current strain on the system reflected a long-running problem.
This needs to be done each autumn to protect against current strains.
Government doctors said the current strain of flu differed in many respects from the 1997 strain.
The researchers say that all current strains circulating in the world are directly related to the medieval bacterium.
But with the current strains on its federal budget, Washington has fallen behind again in finding the money.