frankv:kingdragonfly: Not good news.
A new study has been published in Nature.com.
It involves nine coronavirus cases in Germany.
It suggests that infected people can shed the virus at high levels during the first week of infection.
What is "shed" in this context? Transmit?
The virus is replicating fast, your (lung) tissues etc releasing millions of freshly made virions, pace of replication not slowed by your immune system which hasn't yet ramped up production of antibodies - and plenty of fresh cells in your lungs available for the virus to consume. Respiratory viruses are bad news - because you're coughing them up in this case before you're feeling sick - part of that feeling sick (fever etc) is an aspect of your immune response. Because it's a "novel" (to humans) virus - our immune system is ill adapted to deal with it.