Respiratory Viruses and Flu

Researchers from the University of Maryland ran a controlled clinical trial in a quarantined Baltimore‑area hotel, housing flu‑positive college students with 11 healthy middle‑aged adult volunteers for two weeks to study how influenza spreads in real‑world conditions. The naturally infected students and uninfected adults talked, exercised together, and shared objects like pens and tablets while scientists took daily nasal swabs, saliva and blood samples, and measured exhaled virus using a device called Gesundheit II. According to the study, published in the peer‑reviewed journal PLOS Pathogens, none of the healthy volunteers became infected, which the team attributes mainly to a lack of coughing by sick participants, effective air mixing and dilution in the activity room, and the lower susceptibility of middle‑aged adults. Lead analyst Dr. Jianyu Lai said the data suggest coughing is a "major" driver of flu transmission, while senior investigator Dr. Donald Milton noted that such trials are critical for updating infection‑control guidance that has often assumed airborne spread under a wide range of conditions. The findings land in the middle of a severe U.S. flu season and feed into broader debates, shaped by COVID experience, about the relative importance of masking, ventilation upgrades and behavioral changes in limiting respiratory virus outbreaks.