Viruses have been around for 3.6 billion years. They occur everywhere where there is life. There are about 100 million different types of viruses. Many of them are undiscovered.
A virus is 200 nanometers in small. 1 nanometer = 0.000001 mm.
One gram of human feces contains up to a billion viruses.
A face mask does not protect against viruses.
... and the World Health Organization (WHO) skipped 2 Greek letters - Think about that!!!