Our bodies are constantly invaded with microscopic organisms from outside. It is estimated that every time you brush your teeth, your bloodstream is flooded with bacteria via micro-trauma to your gums. The immune system rapidly recognizes these invaders and neutralizes or destroys them. The same happens with viruses. We have two types of cells in our blood stream. Everyone is familiar with red blood cells, which carry oxygen from our lungs to all the cells in our body. Most people are less familiar with white blood cells, of which there are several types. The ones that primarily concern us when it comes to viruses are lymphocytes. These are part of our lymphatic system that includes our lymph glands, lymph channels, and spleen.
There are two main types of lymphocytes- T and B. T lymphocytes are also called T-killer cells. You have to love the name. They circulate around the body and hunt down cells that are infected with a virus, then destroy them. Picture an army of little ninja assassins except they are on your side. Many will die in the process but, so long as the overall immune system remains functional, they will be replaced by others. The B cells are the ones that produce antibodies. Once exposed to a virus, the B cells will retain a “memory” of the particulars of the virus, such as the specific proteins on its surface. When next exposed to the same virus, the B cells will crank up the machinery necessary to turn our vast numbers of antibodies to neutralize the infection. Simply put, T cells attack viruses inside cells while B cells deal with viruses outside the cells.
As I mentioned at the start, the complexity of our immune system makes the most sophisticated technical accomplishment of humans look positively simplistic, childlike even. The take away here is that we are not defenseless victims of this tiny bit of genetic material that is the virus. The fact that 80% or more of those infected with SARS-CoV-2 will have only mild symptoms or no symptoms at all tells us how effectively we deal with this particular bug.
One aspect of viral infection that I do not see discussed very much is that of viral load. This refers to how much viral exposure you have. Viruses vary greatly in their ability to cause disease. For some, like hepatitis, a single viral particle is enough to make us ill. For others, like HIV and many of the respiratory viruses, such as SARS-CoV-2, it takes a critical level of exposure to lots of virus material, i.e. high viral load, to cause disease in otherwise healthy individuals. This is why our health care workers are especially at risk; they are exposed daily to sick individuals and have ongoing potential to be subjected to high viral load exposures. For most of us, our exposure risk is way lower. We can further reduce our exposure with common sense measures, like avoiding those who are obviously sick. You may ask, “What about those who may be infected but do not know it yet because they have no symptoms?” Well, those people aren’t going to be sneezing and coughing so the most common way of spreading the virus won’t apply to them. What about contact with surfaces on which there may be live virus?
We know this method of transmission is much less common and it can be controlled quite easily. Avoid touching your face with your hands. This precaution is not new. It is recommended to avoid colds and seasonal flu. A lot has been made of wearing gloves and using hand sanitizers, but you cannot wash your hands a hundred times a day and you can only splash on so much Purell. Also, there is no way you are going to wipe down your entire environment 24/7. The simplest thing to do is to strictly avoid touching your face unless you have washed your hands carefully first. This one small measure will probably protect you fully from indirect transmission of the virus.
People are acting as though this virus is some new plague from outer space. It isn’t. We know a lot about it and in the weeks to come will know more. Meanwhile realize that you are not a defenseless victim waiting to be struck down. Follow reasonable steps and you will probably weather this particular storm quite well.
Those people who are truly at risk- the elderly but, even more so, those who have pre-existing medical conditions such as cancer, chronic lung disease, asthma, or are on drugs to suppress the immune system should follow the more extreme self-quarantine guidelines until a vaccine is available.