[Erika]

You are looking for the ID50 (the dose of viral particles that will cause 50% of people to become infected). It’s not known for COVID-19.  For SARS, in mice, the ID50 was several hundred.  A turkey coronavirus looks to require 10^4.88 particles for transmission.

https://pubmed.ncbi.nlm.nih.gov/30146717/

There’s not much data, but it probably requires breathing in hundreds to thousands of viral particles.  Unfortunately, someone who is infected can shed millions of viral particles.

BC

One of the bacterial organisms I was involved in studying was Francissella tularensis which has an astoundingly low ID of 5-10 organisms hence its listing as a select agent (useful to terrorists).

[Erika]

You are looking for the ID50 (the dose of viral particles that will cause 50% of people to become infected). It’s not known for COVID-19.  For SARS, in mice, the ID50 was several hundred.  A turkey coronavirus looks to require 10^4.88 particles for transmission.

https://pubmed.ncbi.nlm.nih.gov/30146717/

There’s not much data, but it probably requires breathing in hundreds to thousands of viral particles.  Unfortunately, someone who is infected can shed millions of viral particles.

BC

One of the bacterial organisms I was involved in studying was Francissella tularensis which has an astoundingly low ID of 5-10 organisms hence its listing as a select agent (useful to terrorists).