Even though scientists have learned a whole lot about COVID-19, this pandemic has also highlighted the fact that there's a lot we don't know about our immune systems. Like, one thing that's really throwing researchers for a loop is that a fair number of people who catch the SARS-CoV-2 virus just… don't show any signs of being infected.
No one's quite sure how prevalent these symptomless, or asymptomatic cases are.
And that's especially concerning for a disease that lands between five and thirty percent of people in the hospital!
What researchers are fairly sure of, though, is that there isn't one answer to why people don't feel the effects of SARS-CoV-2.
And looking deeper into many of the potential explanations will teach us a lot about how our bodies fight pathogens.
Now, technically, everyone with COVID-19 starts out symptom-free, or presymptomatic.
No one is coughing the instant the first virus gets into one of their cells and convinces it to start churning out more viruses.
There is an incubation period, and it can take anywhere from a few days to two weeks for people to start to feel an infection.
Also, what "feeling it" looks like varies.
It could be milder signs like a duller sense of taste or smell, all the way to life-threatening breathing difficulties or heart problems. Doesn't matter where a person falls on that spectrum; even mild symptoms make a case count as a symptomatic infection.
