The influenza D virus that researchers say has been flying under the radar since its detection in animals in 2011 can vigorously make copies of itself in human cells and lung tissue samples, a new study shows.

The findings suggest influenza D has strong potential to spill over to humans, the scientists say.

Some people who work with cattle, considered the primary host for this virus, have been found to have influenza D antibodies in their blood, but no active human infection has been discovered to date.

Results showed that several genetically different strains of influenza D that were isolated from cattle and pigs, another animal host, were as effective at replicating in cells from the human respiratory tract as influenza A viruses – the types of flu linked to both modern seasonal illness and historic pandemics.

“All of the viruses, despite their genetic distance from eac…