ou call a friend and arrange to meet for lunch. It’s unseasonably springlike, so you choose a place with outdoor seating, which seems like it should be safer. As usual, you take all reasonable precautions: You use hand sanitizer, sit a good distance from other customers, and try to avoid touching your face, though that last part is hard. A part of you suspects that this whole thing might be overblown.

What you don’t know is that ten days ago, your friend’s father was a guest of his business partner at the University Club, where he caught the novel coronavirus from the wife of a cryptocurrency speculator. Three days after that, he coughed into his hand before opening the door of his apartment to welcome his son home. The saliva of COVID-19 patients can harbor half a trillion virus particles per teaspoon, and a cough aerosolizes it into a diffuse mist. As your friend walked through the door he took a breath and 32,456 virus particles settled onto the lining of his mouth and throat.

Viruses have been multiplying inside his body ever since. And as he talks, the passage of his breath over the moist lining of his upper throat creates tiny droplets of virus-laden mucus that waft invisibly into the air over your table. Some settle on the as-yet-uneaten food on your plate, some drift onto your fingers, others are drawn into your nasal sinus or settle into your throat. By the time you extend your hand to shake good-bye, your body is carrying 43,654 virus particles. By the time you’re done shaking hands, that number is up to 312,405.

https://nymag.com/intelligencer/2020/03/the-story-of-a-coronavirus-infection.html

Someone tweeted on 16 Nov. 2015 that
“A lab-made Bat Coronavirus related to SARS has been shown to infect human cells.”
This tweet was in response to a 12 Nov. 2015 article at Nature [dot com] , an international journal of science, titled
ENGINEERED BAT VIRUS STIRS DEBATE OVER RISKY RESEARCH
Lab Made Coronavirus Related To SARS Can Infect Human Cells
By: Declan Butler
The first paragraph states:
“An experiment that created a hybrid version of a Bat Coronavirus — one related to the virus that causes SARS (Severe Acute Respiratory Syndrome) — has triggered renewed debate over whether engineering lab variants of viruses with possible pandemic potential is worth the risks.”
I think that the article’s question has now been answered.