Dr. MeiLan Han
A Costly Game of Telephone
I’ve been thinking a lot about what we’ve learned during the pandemic and how it has shaped our scientific understanding of respiratory viruses. One thing you may not realize is that our understanding of how most respiratory viruses are transmitted significantly shifted during the pandemic. Actually, let me restate that. Our understanding of respiratory virus transmission and how we can protect ourselves has been forever changed.
Previously we thought droplet transmission was the primary mode of transmission. These are larger particles created when we cough or sneeze. These heavier particles don’t hang in the air very long before falling to the ground. This is why we focused initial public health measures on social distancing and hand washing. But at the beginning of the pandemic, we relied on accepted scientific thought that only very tiny particles, less than five microns, would remain airborne.
We were wrong. In fact, we had been wrong for a really long time.
The results from a study dating back to 1962 had been misinterpreted. What we realized is that SARS-CoV-2, the virus that causes Covid-19, is transmitted largely through aerosols. These smaller respiratory particles hang in the air much longer. This is why public health measures shifted to masks and improved ventilation systems. This also means that moving forward, we now realize these same measures can decrease the risk of contracting other viruses. Coronaviruses are also a cause of the common cold, for instance. If we want to protect vulnerable individuals, wearing masks could be a lot more common in the future. Some healthcare workers may choose to wear masks as common practice. Even flu outbreaks that we had prior to the pandemic, could potentially be halted or slowed based on what we’ve learned. Of course, I’m as desperate as everyone else to return to “normalcy” but I think some mask-wearing will be part of our new normal.
To learn more, check out my new book, Breathing Lessons: A Doctor's Guide to Lung Health.