Key Takeaways

Air filters don’t help prevent the spread of respiratory viruses at school

Air samples revealed the presence of an average of three and as many as 13 viruses in classrooms, despite HEPA filtration

Low humidity appeared to play a more direct role in virus transmission

WEDNESDAY, Oct. 15, 2025 (HealthDay News) — School is back in session and with it, the beginning of the cold and flu season.

Unfortunately, air purifiers aren’t likely to reduce the risk of children’s exposure to respiratory viruses in the classroom, researchers reported Oct. 10 in JAMA Network Open .

Even high-efficiency particulate air (HEPA) filters didn’t stop the spread of airborne viruses, the study found.

“We found that air samples from classrooms included in our study had an average of three di

See Full Page