Is that for sure a thing with viruses that the more you originally take it, the sicker you get? You sure would think it would matter but I've never heard about it before this whole deal.
It is generally true the more virus initially the less your body can destroy it because it with a new virus like covid 19 your body has to react and make antibodies ( this info according to my wife the MD and some things I read that sometimes the body make take days to really start attacking the invaders thus the long incubation periods). Plus the more virus the more cells it invades and the more millions of new viruses it makes so the exponential spread is going on in the body.
And I am not sure if you are aware of the gene therapy techniques using viruses to carry in genetic material to be introduced into a person's cells as a cure for genetic illnesses. The genetic material is supposed to do a recombinant DNA action to put good genes in cells for a cure. Well the first time this was done the doctors introduced too much virus plus this young patient's body reacted violently to the invading virus and he died. Viral gene therapy died also that day for 10-15 years until they found a better way to introduce the new DNA using a patient's own stem cells so no rejection.
We just saw much of this info on a really good PBS show about genetics called perhaps called The Gene. It is an excellent show at least a few hours going over the history, science, investigations, and medical aspects.
It is a Ken Burns doc https://www.pbs.org/show/gene/