Sorry for the rant, feel free to not read it.

I'm also simplifying stuff (from a science standpoint this can be rather complicated, since there are lots of nuances between many virus types). So as with all viral infections, those who carry viruses do so only with a certain amount regardless of the virus type. There are exceptions but I don't think that SARS-CoV-1 or 2 are within those, since they're a coronavirus like any other. The actual problem is that this type of Coronavirus has unstable RNA, which means that it may mutate to change its type so it may (or may not) become really dangerous (or it doesn't). Again, there are indications which already show that it actually gets less lethal over time but things may change as well, you may think of the evolution of the virus as a sort of a sinuscurve, with ebbs and flows. As a rule of thumb, most viruses don't want their hosts to get killed as well, which is something you can always consider. So while there is reason to be alarmed, there is no need to panic as many first world country populations do right now, such as buying toiletpaper like its the antidote against the Coronavirus :D.

At any case, right now you probably have several dozens of illnesses impacting you in minimalistic ways that you don't know anything about, yet no test would indicate that you're infected with some sort of dangerous disease, even though you may have one. Its simply because your threshold hasn't been met and your body can fend off any of these common diseases. Those who already have any sort of illness naturally have a lower threshold (because their metabolism is occupied fending it off the already dominating type of virus) which means that the body in general becomes weaker to ALL kinds of viruses and doesn't have the chemical balance to create neutralizing antibodies (NAb in short), which depending on the chemical balance of the NAb, will then serve as a counter towards the virus.

However, even if you have a slight amount of a certain type of virus inside you, it can still get outside your body (through the usual means) and there are always chances to infect others. Even though the amount is insignificant to most people, those with a slightly irregular immune system could still be affected by the host of illnesses that you carry around with you (and so does anyone else). However, since SARS-CoV-2 is very new, the chances to get sick become very high to those with a irregular immune system. This is not a huge problem form a science standpoint because this is a common occurance and those people who're actually virologists understand this very well. I'm fairly sure that within half a year things will looks much better. I mostly worry about the aftermath of the virus though, the economy might take some time to recover.

For instance, from what I understood, SARS-CoV-2 REALLY doesn't really like NAb's so theres a good sign that a antivirus that can be scaled to even counter a pandemia quite quickly and cheaply. I'm no expert though and I don't know all the details, like the metagenomics and stuff like that.

EDIT: Or just look at sanscripts post. He wrote the same stuff as I did but its shorter. Not a fan of Youtube posts though as I feel its better to explain things in a discussion it rather than just link to videos (through its a good way to occupy yourself with and from skipping threw the videos they also aren't wrong, so feel free to entertain yourself with some education). I should've refreshed next time before typing up a post, but then I would've not occupied myself with posting. What a dilemma :D!