My understanding of the infection process for viruses (such as SARS-COV-19) is that when one or more viruses get past the physical defenses (mucous, stomach acid, etc) they inject their RNA payload into a cell, and produce more copies of the virus. This is an exponential growth process, dealing exponential damage to the body with time.
Of course, having 100 cells out of trillions get infected and killed is completely unnoticeable, but if the infection grows to millions, that starts to have an impact.
The body then has a step-wise defense. First there are general purpose immune response cells that catch and kill generic intruders. So, if you literally had one copy of a virus get in, it (or it's children or grandchildren) would just get rounded up and disposed of without any impact. This happens all the time, as there are viruses everywhere and we are constantly bombarded by a low level of self-replicating intruders.
If the initial (or repeated) exposure generates enough of the same virus, the body creates a set of special response cells (T-cells), which provide a super-exponential response (the T-cells are not consumed as they dismantle viruses, and they replicate exponentially), which allows the immune system to catch up to the viral growth and get rid of it.
In some cases a Fever or other bio-kinetic response can make your body a less hospitable environment for the invader.
The general malaise and "feeling sick" comes from a combination of your cells dying to the virus, and your body re-directing energy away from normal maintenance & activity to produce enough immune response cells to catch up to the exponential growth.
First there are general purpose immune response cells that catch and kill generic intruders. So, if you literally had one copy of a virus get in, it (or it's children or grandchildren) would just get rounded up and disposed of without any impact.
So the general purpose immune response cells can kill X viruses/minute and if there are to many they have a problem?
Injecting RNA into cells is not enough. There are also interferon protein complexes that interfere with viral RNA doing anything inside the cells. They must be bypassed or overrun or there will be no viral replication. These intracellular defenses make many viral infections grow much slower.
There's room to expand on the bit about how live virus particles might reach your respiratory system:
Physical contact between mucosa and contaminated surface. The degenerate case of this would be if someone wiped their hand along a surface that an infectious person had coughed on and immediately picked their nose: droplets could get from the infected person to the mucosa of the person with poor hygiene without the latter technically inhaling them.
Eye contact. A literature review from October on the subject seemed inconclusive, but can't rule it out. There's also the much-talked-about paper on lower COVID rates among glasses-wearers. Since tear ducts drain into the nose, the "stuff that gets in your eyes ends up near your respiratory system" link seems plausible enough to take seriously until better research on the topic becomes available.
There's also the much-talked-about paper on lower COVID rates among glasses-wearers.
I think that could just translate into nerds who spend less time with other people and have an easier time isolating are less likely to get COVID.
I read a bit but don't know how good my understanding is. For reasoning about TAFFIX or the RaDVaC vaccine it would be good to have a decent gears model. I'm writing my current model so that others can check it for errors and not for others believing my model:
There's SARS-CoV-2 particles in the air around you.
You breath in those particles.
If your nasal cavity is lined with mucus, those particles get onto the mucus and the mucus traps them. The mucus however itself doesn't kill SARS-CoV-2 particles in it.
There are two ways of getting rid of the mucus with the SARS-CoV-2 particles. Either you blow your nose and get rid of the mucus in your nasal cavity that way or you shallow it.
If the body knows how to defend against SARS-CoV-2 from a previous infection it puts antibodies inside the mucus to bind the SARS-CoV-2 particles. If the SARS-CoV-2 particles however aren't bound they sometimes get again into the inhaled air and make it into the lung or the go from the mucus into the nasal tissue.
Once antigens enter the nasal tissue, the mucosal immune system starts producing antibodies for those antigens so that they get trapped in the mucus and in the nasal tissue.
If there are too much SARS-CoV-2 particles the immune system in the nasal tissue doesn't manage to handle the threat in time, the SARS-CoV-2 particles grow in quantity. The get into the lymph and blood and travel through the body. Then the normal immune system kicks in and tries to fight it. If there aren't many particles it somehow manages to fight it (so that there's a threshold for infection) but if there are too much it first has to go through effort to build up the immune system defenses and there's a COVID-19 infection.
Is there something wrong in my recounting or something important I'm missing? I'm also happy of other resources that give a clear gears model.