We have all heard about
factors that can contribute to a bad, even deadly, experience with COVID-19. Factors such as age, gender, and underlying conditions.
But the article linked below, from the NPR website, notes that there is something else going on that can also be an important factor in coming to have a bad experience with COVID-19. Or actually any viral illness for that matter. It involves something called "viral load."
For my part, I had always assumed that when it comes to being exposed to and infected by illness-causing viruses, such as by breathing them in, the number of viruses inhaled didn't matter, as taking in even a small number of them would be sufficient to start the disease-causing process.
But according to the article below this is not true, and the larger the "viral load" of germs taken in during an exposure, the greater the chance of contracting a serious episode of the illness.
From the article:"Does the size of a viral dose make a difference? That is, if you're exposed to lots of viral particles, will you get sicker? While there is a lot we don't know about SARS-CoV-2, experts believe they can answer this question with confidence: Yes – the amount of virus a person is exposed to makes a difference in whether they get sick and how sick they get."
"Every virus, if you get one particle of virus, you're likely to never know it – you're also likely to really never get sick and never develop an immune response. And for most acute viruses, there is a gray area where you get some version of sick but not horribly sick — and develop an immune response that is protective against the virus in the future."
"If you have someone working in an intensive care unit and the poor physician or the poor nurse gets a hefty dose, then the severity of the disease really is much worse than if one just gets a single particle."
Well, I didn't know that.
And the obvious implication from all this is that minimizing intake of massive quantities of viruses helps to increase one's odds of avoiding a bad case of disease.
Hence, avoidance measures such as wearing masks ("dose-reducing agents," the article calls them), hand-washing, and staying clear of areas with likely high virus-per-unit-area counts will pay off.
Apparently, then, if our bodies are exposed to just a handful of even serious viruses, our immune systems can fight them off. But if it's a massive number, it seems to be as if our systems get overwhelmed by the sheer number of them, and disease follows.