Aren’t all the doublings local?
Introducing the virus like this, you’ve created a live virus vaccine. The work involved in creating and testing such a vaccine isn’t really any less than creating the vaccines we did make. You still have to develop technology to grow the virus and distribute exactly the right quantity. Moreover, the risk of complications is far greater if someone fails to fight off the small viral load infection.
The vaccines such as Moderna only took a week or two to prototype in January 2020. The entire rest of the time was scaling up production and running tests to prove it worked in the population. We could have skipped running the trials and deployed the untested vaccine instead. A lot of lives would have been saved but no way to know that without doing the trials, I suppose.
That was also my intuitive response at the beginning of the pandemic. I assume one virus was plenty due to exponential growth. Having read every article I could in the past year, it's extremely rare to run across any details but:
1. I've read that scientists believe a coronavirus takes hundreds of viruses to successfully infect us. Not, for example, several dozen like some other viruses.
2. Next obvious question to me is, is this because one has to land on a lucky spot on the body and the rest somehow die before they can reproduce (so it's statistical odds that one virus gets the conditions it needs just like one sperm makes it to the egg)? Or can the body fight off a dozen or two dozen covid19 viruses so quickly that they never take hold? I only see two possibilities here.
3. If it is the latter, an answer I can't find anywhere, why did we need to waste so much time developing a vaccine? Wouldn't it be equally efficacious to introduce one virus to the body on day one, four on day two, and so on until immunity is achieved? Evidence of this possibility would be mixed in with the population they believe are asymptomatic, so unless researchers look for this they won't find it. (Basically a natural immunity hypothesis - based on repeated low viral count exposure.)