The Atlantic reported that the lung specimen, taken from a girl who died of pneumonia after a measles infection in 1912, had been sitting in the basement of the Berlin Museum of Medical History at the Charité.

Now more than a century after her death, the team led by Calvignac-Spencer, a virologist at the Robert Koch Institute, has managed to sequence the measles virus in the girl’s lungs. It is by far the oldest measles genome ever assembled. And by comparing that 1912 measles virus to more modern strains and to related animal viruses, the team pushed back the earliest likely date that measles could have emerged in humans to 400 b.c., 1,500 years earlier than estimated with previous genetic evidence. 

“With viruses, we don’t have fossils,” says Calvignac-Spencer. But in recent years, scientists have started rummaging through old pathology collections and using computational models to trace the otherwise lost history of viruses. Calvignac-Spencer thought he might do the same for measles, which is why he got in touch with the Berlin Museum of Medical History at the Charité. The museum was eager to collaborate and to find new uses for its extensive pathology collection.