Since knowledge is powerand sometimes has anxiety-reducing powerwe spoke with Ben Neuman, Ph.D., head of the biology department at Texas A&M University-Texarkana.

Hes a researcher who has worked with coronaviruses for 24 years, and here, he simplifies the complex process of how your body tries to fend off the coronavirus that causes COVID-19, and what happens when it cant.

On an average day, your body is always on the lookout for invaders

Every cell has to report to the immune system what its making at the time, explains Neuman. There are special molecules that do this. They sort of grab a little sample of whatever were doing and hold it up and say to other systems in the body, hey guys, what do you think about this?

When your body finds an invader like this coronavirus, it takes action

Usually when your body detects an invader, it activates your innate immune response to fight off the virus in a general way until it can kick its smarter, more specific adaptive immune response into gear. This second line of defense starts a whole, amazing cascade that includes the manufacture of killer T cells. Their job is to go in and punch holes in any cell that is infected with the virus, he explains, rendering it impotent. They recognize, detect, and destroy. In people who survive infections with coronaviruses and do well, if you check their blood afterward, as we found with SARS, you find out that they have a really good killer T cell response. And the ones who dont do well did not really make a killer T cell response.

But coronaviruses try to remain undetected

Like any virus, the new coronavirus that causes COVID-19 is promiscuous and narcissisticit wants to make as many replicas of itself as possible. Its not its intention to kill people, although sometimes it ends up doing that. It just wants to keep itself going, so it attaches itself to your cells, injects its RNA in there and reprograms the cell to turn into a virus and reproduce itself in the form of more viruses.

Your body has a system, called the interferon pathway, thats like a cry for help that the immune system sends to cells, or that cells send to the immune system, explains Neuman. Its a communication molecule. And the coronavirus goes to great lengths to short-circuit that pathway. Its trying to silence it by any means necessary so that the virus can just grow in peace. If you manage to get the signal out in time, you can shut down the coronavirus and make a really good immune response. But if you make the wrong response, the coronavirus wins.

Where coronaviruses like to live in your body

Coronaviruses and flu viruses like to go into the surface of the lungthe part where air is touching the cellsand then they like to go right back out where they came from so they can infect somebody else. And theyre pretty good at it, Neuman says. But they dont actually have a brain, and theyre not perfect. So occasionally, one of them will get on, the wrong highway, basically, and end up in the bloodstream.

Normally, our immune system is waiting there to pound these viruses into dirt so they cant do anything. If it doesnt, the virus can end up in the bloodstream and create all kinds of havoc. This virus grows well in the liver, explains Neuman, but it shouldnt ever get there because your liver isnt hooked up to your lungs. Same with the spleen and the intestine. Youll see something like five percent of people having SARS-induced diarrhea, and in severe cases, it may be able to get to your brainstem. Thats what controls breathing and heartbeat, and theres some evidence from the old SARS outbreak that it was able to get there, but only once everything else had broken down.

If youre immunocompromised, your body doesnt tackle these viruses as well

Ideally, your body creates a balanced immune response to invaders. But if you are immunocompromisedmaybe youre getting cancer treatment, or have an organ transplant, or are HIV positive, or otherwise have a suppressed immune systemthat means that balanced response may not be possible. So unfortunately, the best option is to take steps not to get the virus. Which means doing everything you already know (but heres the info , anyway).

Even if youre not immunocompromised, the virus may take advantage of you

The respiratory symptoms that come with this disease, especially in severe cases, happen as a result of your body trying to protect itself. When the virus infects the middle to the bottom of the lung, which this coronavirus likes to do, your body sends out cells to stop that. Your body takes a scorched-earth policysome cells go through your lungs and just try to wreck the place, destroying healthy tissue. If there are no living cells there, then the virus cant get into them and it cant do anything to you, Neuman explains.

And in severe cases, your lung capacity gets smaller

While that scorched-earth policy is protecting you from an advancing invasion, its also reducing your lung capacity. Your body tries to bring that capacity back, but its not always the most peaceful process. Its like if you were doing repairs on a big medieval cathedral, theyd fill the entire inside with scaffolding to support everything. And then they start taking out bricks and you know, changing things around. So some of the places where the air should be inside the alveoli [the air sacs in your lungs] are taken up. Eventually, that will go awaythe scaffolding will come down and youll be able to breathe again, Neuman says. But that process takes a couple of months. And you need to breathe during that time. So a lot of people with the severe version would need some additional support by getting extra oxygen to the lungs. There are even people who have been immunocompromised and who have been just in terrible shape and they've managed to keep these people alive for months and months with SARS and MERS. It can be done. But it does take a lot of resources from a hospital.

What to do to keep your immune system running well

The idea that you can boost your immune system rubs doctors the wrong way, because too energized of an immune system causes the body to attack itselfthats what an autoimmune disease looks like (not that you have any control over it; in those cases, the immune system went into overdrive on its own).

But you can at least be sure that yours is running optimally by giving your body a chance to repair, relax and rest, explains Neuman. Thats exactly what they would do in a hospitalgive you bed rest and fluids, just to be sure everything keeps running as well as it can. Then its just a matter of waiting out the virus.

Does hand washing help you avoid it? Neuman says soap is great in inactivating the virus. And that hand sanitizers with alcohol can, too, but not instantly. The alcohol denatures the coating of the virus a bit, but its not until the alcohol evaporates that it punches a hole in the virus and kills it. Thats why you have to let hand sanitizer dry on its own and avoid wiping off any extra before it has dried.