If you're one of the people who has had the new coronavirus take hold in your body, what exactly does it do to you?
Since knowledge is power – and sometimes has anxiety-reducing power – we spoke with Ben Neuman, PhD, head of the biology department at Texas A&M University-Texarkana.
He’s 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 can’t.
On an average day, your body is always on the lookout for invaders
“Every cell has to report to the immune system what it’s making at the time,” says Neuman. “There are special molecules that do this. They sort of grab a little sample of whatever we’re 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 the new coronavirus, it takes action
Usually when your body detects a hostile alien cell, 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 defence 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,” Neuman says. This renders the intruder impotent. “They recognise, 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 don’t 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 narcissistic – it wants to make as many replicas of itself as possible. It’s 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, “that’s like a cry for help that the immune system sends to cells, or that cells send to the immune system,” says Neuman. “It’s a communication molecule. And the coronavirus goes to great lengths to short-circuit that pathway. It’s 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 lung – the part where air is touching the cells – and then they like to go right back out where they came from so they can infect somebody else. And they’re pretty good at it,” Neuman says. “But they don’t actually have a brain, and they’re 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 can’t do anything.” If it doesn’t, the virus can end up in the bloodstream and create all kinds of havoc. This virus grows well in the liver but it shouldn’t ever get there because your liver isn’t hooked up to your lungs. Same with the spleen and the intestine. You’ll see something like five per cent of people having Sars-induced diarrhoea, and in severe cases, it may be able to get to your brainstem. That’s what controls breathing and heartbeat, and there’s some evidence from the old Sars outbreak that it was able to get there, but only once everything else had broken down.”
If you’re immunocompromised, your body doesn’t tackle these viruses as well
Ideally, your body creates a balanced immune response to invaders. But if you are immunocompromised – maybe you’re getting cancer treatment, have an organ transplant, are HIV positive, or otherwise have a suppressed immune system – “that 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 here’s the info, anyway).
Even if you’re not immunocompromised, the virus can still 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 policy – some 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 can’t get into them and it can’t do anything to you."
And in severe cases, your lung capacity gets smaller
While that scorched-earth policy is protecting you from an advancing invasion, it’s also reducing your lung capacity. Your body tries to bring that capacity back, but it’s not always the most peaceful process. “It’s like if you were doing repairs on a big medieval cathedral, they’d 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 away – the scaffolding will come down and you’ll be able to breathe again.
“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. 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 energised of an immune system causes the body to attack itself – that’s 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, says Neuman. “That’s exactly what they would do in a hospital – give you bed rest and fluids, just to be sure everything keeps running as well as it can. Then it’s 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 sanitisers with alcohol can, too, but not instantly. The alcohol denatures the coating of the virus a bit, but it’s not until the alcohol evaporates that it punches a hole in the virus and kills it. That’s why you have to let hand sanitiser dry on its own and avoid wiping off any extra.
The information in this story is accurate as of the publication date. While we are attempting to keep our content as up-to-date as possible, the situation surrounding the coronavirus pandemic continues to develop rapidly, so it's possible that some information and recommendations may have changed since publishing. For any concerns and latest advice, visit the World Health Organisation. If you're in the UK, the National Health Service can also provide useful information and support, while US users can contact the Center for Disease Control and Prevention.
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