[M T]

One of the questions relative to a number of things is how many virons does it take (on average) to cause an infection.  Could the rate of distinct genomes in people suggest a range?

This is far out of my ken, but maybe someone here has seen work along these lines.  Or maybe tell me this isn't how things work.

Suppose it takes only one viron to start replicating and make you sick, and the rate of viable mutations of any replication in the infector was 1 in 1000, then if the infectee became got exposed to a single viron, which then replicated, then the rate of mutations in the viruses in people should be 1 in 1000.

If it took 1000 virons to start replicating before you immune system can't stop it, then most of them would be be the same as the original genome in the infector.  Most of the replicated viruses would be the same genome.  The mutated viron would need to have some replication advantage to become the prevalent genome in the infectee.

If all that is true, then the rate at which genomes change from case to case might suggest how many virons it takes to infect someone.

There's still the issue that you might get 1M virons even if it only takes one to get you sick. 
It may be that 1 viron in the lower lungs is enough, but 1M are necessary in your throat.

Apparently, the Iceland research has the genome for each individual that got sick.

[M T]

One of the questions relative to a number of things is how many virons does it take (on average) to cause an infection.  Could the rate of distinct genomes in people suggest a range?

This is far out of my ken, but maybe someone here has seen work along these lines.  Or maybe tell me this isn't how things work.

Suppose it takes only one viron to start replicating and make you sick, and the rate of viable mutations of any replication in the infector was 1 in 1000, then if the infectee became got exposed to a single viron, which then replicated, then the rate of mutations in the viruses in people should be 1 in 1000.

If it took 1000 virons to start replicating before you immune system can't stop it, then most of them would be be the same as the original genome in the infector.  Most of the replicated viruses would be the same genome.  The mutated viron would need to have some replication advantage to become the prevalent genome in the infectee.

If all that is true, then the rate at which genomes change from case to case might suggest how many virons it takes to infect someone.

There's still the issue that you might get 1M virons even if it only takes one to get you sick. 
It may be that 1 viron in the lower lungs is enough, but 1M are necessary in your throat.

Apparently, the Iceland research has the genome for each individual that got sick.