Our Human Biome is the first line of defense. It's all of the microbes that live on the skin that have achieved their own equilibrium and can kill invaders. Then it's the innate immune system we were born with, or we would not have survived a week. Those cells, mast cells, phagocytes, and macrophages can kill the invaders, send out chemical signals that they need help, and even convince infected cells to commit suicide to save the rest. The remnants of the killed viruses at this stage is what the PCR test is identifying.

If all that fails, they notify the adaptive immune system to send in the cavalry which activates T and B cells that remember the invader and the next time can activate without all the other hoopla. The antibodies that the B cells create is what the serologic blood test identifies, but they decrease with time so you can still test negative even if you have been proven to have had covid.

Most of the time, our innate immune system can take care of the problem and we never know or mild symptoms go away quickly. Vaccines boost the adaptive system but sometimes that fails. Many viruses can change their protein coat up to 30 times like a cloaking device. They can secrete chemicals that kill or disable the cells defending us. They can even pluck some of our DNA into themselves so our cells identify them as our own rather than invaders. The antibodies are on the way and then can't find their counterparts to bind to and destroy.

Remember, invaders can enter through cuts in the skin, GI Tract, Nasopharynx, Mucous Membranes, insect and animal bites, and even the Eyes. And each system has its own unique defense mechanisms such as enzymes and acids, besides the systemic ones from the blood and bone marrow.

Viruses can mutate as well, genetic and antigenic drift is a slower process, like the flu where we need a new vaccine every year and that seems to suffice. Antigenic shift is a major change in the structure and makeup of the viral antigens (maybe even between different species) where suddenly, the population has no immunity against a familiar disease, our cells can't defend against it or perhaps an animal virus is now able to infect humans for the first time.

It will be regular flu season very soon, which can also be deadly. It typically kills 30,000 to 50,000 or more each year in the US. Auto accidents claim 30,000 to 50,000 per year. What is the right thing to do?

It would make more sense to isolate the sick and the immunologically compromised and everyone take proactive measures to boost our immune systems because we never stop needing them. It's not like there is one covid virus 3 blocks away that we have to avoid, we are awash with all kinds of microbes that wage a very sophisticated war, invading and defending.

Healthy people should not be isolated or breathe through filthy masks. (Not many dispose of or clean and disinfect them at least once per day.) The immune system is meant to operate all the time. Use it or lose it.