When infected with the Middle East respiratory syndrome coronavirus (MERS-CoV), camels come down with a week-long illness and spew high quantities of pathogen into the air. The commonly-infected mammals have thus been blamed as vectors of the deadly MERS outbreak that has affected nearly 950 people—killing at least 350—since it began in 2012.

But according to a study to be published in a coming issue of Emerging Infectious Diseases, MERS-infected camels may not be spreading the coronavirus to humans.