The researchers who are recreating the strain of influenza that resulted in the 1918 global pandemic had this to say about the potential risk (boldface mine):
The scientists involved in the project contend there’s no real risk to public safety. The vials of this frightening germ — about 10 of them — are locked away at the federal Centers for Disease Control and Prevention in Atlanta, said Terrence Tumpey, the CDC research scientist who constructed the virus.
As many as 75 scientists from the Centers for Disease Control and Prevention may have been exposed to live anthrax bacteria after potentially infectious samples were sent to laboratories unequipped to handle dangerous pathogens, a spokesman for the federal health agency said Thursday.
The agency was testing a new way to kill anthrax, which they discovered did not work as well as they expected.
…The lapse occurred sometime from June 6 to June 13. Workers in three labs who were not wearing protective gear moved and experimented with samples of the highly infectious bacteria that were supposed to have been deactivated, the agency said.
It added in a statement that procedures used in two of those laboratories in Atlanta, where the C.D.C. is based, may have “aerosolized the spores,” essentially blowing the bacteria into the air. The exposure was discovered June 13, when the bacterial plates were collected for disposal and live B. anthracis colonies, or anthrax bacteria, were found.
Regarding the recreated flu strains, we are dealing with a question of when, not if.
Nothing to worry about, though.