I know that you know when you are ill. What you don't know is when you have been infected with a virus but not become ill as a result. Anyway, that is not the point.
I will leave it to someone more knowledgeable to summarise the article if they wish to. I don't think it will help you though. It is about research which is ongoing and which may lead to changes in medical treatment or vaccine development. It doesn't indicate a way for you to predict who is at risk and it doesn't involve any tips you can self administer. We are all waiting for the results of this type of research to filter through to changes in hospital or primary care for covid patients, which will be managed by medical professionals.
Also, I really think it would help you to take a break from seeking in depth information about this. It isn't making you feel empowered or giving you any actionable knowledge, or even satisfying intellectual curiosity. At least it doesn't seem that it is.
I have been extremely unwell with anxiety in the past and in that state I felt like I was seeking information, looking for one fact that could help me or end my worries. In reality though, I was not seeking information. I was seeking complete reassurance and an end to all uncertainty, in a place where I would never find it. Do you think something similar might be happening to you?
We can't ever feel confident of zero risk in life, risk is always there. How much fear or attention we pay to it is often not reflective of the nature of the risk. If you keep seeking reassurance, you will reinforce to your brain that this is a huge risk and not only that, it is one you can do something about...keep looking for more information as you need to do something about the risk. The worry is red flagged in your mind as something you need to address, so you keep looking for more information and that flags it more..and so on..
I may be completely off base so please excuse me if so. I am only trying to help but ignore me if I off on a tangent. I just get the feeling that maybe the attempt to look at all this information, which might be great for you at another time, is right now just counter productive and fuelling your anxiety. I know from extremely bitter experience that the longer these things go on the harder they are to stop.
If that feels like it might be the case, and again forgive me if not, maybe try to step back from seeking information at the moment. Try to live with not being able to totally control the risk, to live with not knowing. At first it will seem impossible, but the less you attempt to eliminate all doubt the easier it will get. Every time you tell yourself you don't need to seek more reassurance the worry will start to seem that little bit less important, less flagged up by the brain. Eventually the mind will see the worry as something you don't need to deal with, but just to live with.
If you think that you tend to get sicker with infections than you would expect, maybe give your GP a call and ask whether any problem is indicated or if you need to do anything, rather than trying to answer it yourself right now. Other than that just take normal care of yourself including your mind.