It's not surprising if you understand how HEPA filters work, the particulate sizes that they're effective for, and the particulate sizes of viruses. Most people

It's not surprising if you understand how HEPA filters work, the particulate sizes that they're effective for, and the particulate sizes of viruses. Most people are not familiar with one or more of those things, so these stories are worth amplifying to the end of the earth and back, so that we can be better prepared to deal with this pandemic and the next.