Four samples were sent to the Michigan's State Laboratory in North Lansing and two to Sparrow Hospital's Microbiology Department.
These labs routinely are sent different viruses as part of a proficiency test in which they are asked to identify the virus.
They usually are sent strains seen in recent years, but this one has not been seen since 1968. And the strain is responsible for a global pandemic in 1957 and 1958 which killed millions of people.
Dr. Maria Patterson of Michigan State University's microbiology department says the decision to send the strain was most likely an oversight.
The World Health Organization has launched an alert for all labs to destroy the virus samples. Both labs in Mid-Michigan have already done so, but workers there will be closely monitored.
The concern is if a worker was exposed, he or she could potentially spread the virus and start another pandemic.
Anyone born after 1968 probably does not have any immunity to this H2N2 strain. At this point the World Health Organization does not report anyone has been infected.