Although president Donald Trump is no longer in the hospital, his experience with Covid-19 hasn’t been a walk in the park. He received the steroid dexamethasone, which has been authorized for use in severe coronavirus cases, the antiviral drug remdesivir, and an experimental treatment of antibodies that he will continue for the next few days. It’s not clear what the long-term effects of Covid-19—or its treatments—could be on his health as a 74-year-old man.
It’s the same for any older adult who gets sick with Covid-19 and survives, says Candace Brown, a professor of gerontology at the University of North Carolina, Charlotte. Even the healthiest older adults aren’t as well equipped to recover from a novel infection as their younger selves.
Doctors know to check for co-morbidities, which are more common in older adults and can make the virus harder to fight off. But those are the risks they know. “I’d be concerned about conditions that [we] don’t know about,” Brown says.
Trump is part of a population that’s at high risk of severe cases of Covid-19. Scientists have observed that the highest death rates from Covid-19 have been among men in their 70s or older. and for those who make it through, their path to short-term and long-term recovery isn’t clear. To understand why, we have to look at how infectious diseases hit older people differently.
The anatomy of an older adult
In general, the longer you’ve been on Earth, the harder it gets to stick around.
One part of the body that gets hits hard over time is the respiratory system. “Even with regular age-related changes, we’ve got a decrease in the lungs’ ability to exchange oxygen and carbon dioxide,” says Brown. That leaves older lungs more vulnerable to Covid-19.
This happens for a couple of reasons. First, the diaphragm and the intercostal muscles along the ribs get weaker, making it harder for the lungs to expand. Second, the lung tissue itself becomes stiffer, making it harder to move air around its pockets. Both of these leave the lungs with less surface area to carry out their gaseous import/export business.
Then there’s the heart, which powers the main conveyer belt of these gases. Older hearts tend to grow bigger over time; fat also accumulates around them, which makes it harder for them to beat quickly, Brown says. The electrical signals that power them slow down over time too, while arteries, which pump out freshly oxygenated blood, harden. In general, it becomes more challenging to circulate not just oxygen, but nutrients and waste to be excreted.
The degree to which two systems change over time depends largely on the person taking care of them. Someone exercising regularly in their 60s or 70s may not experience the same degree of chest cavity muscle loss or heart enlargement as someone who leads a more sedentary lifestyle. Added conditions like hypertension, COPD, or diabetes can exacerbate these changes even more.
Both of these organ systems are connected to every other system in the body. “When you have one part of your body system that isn’t working to the best of its capacity, then everything else won’t work as well,” Brown says. Throwing a wrench like an infectious disease in the mix makes things even more complicated.
Aging immunity
Even though the immune system is supposed to keep the body safe from pathogens, it doesn’t always work that way. Sometimes, if the body generates a particularly intense immune response, it’ll end up doing more harm than good. And that’s more likely to happen the older we get.
Broadly, the body’s immune system can be broken up into two categories: the innate and adaptive responses. The innate response is less specific—and therefore more aggressive. The adaptive immune system consists of things like antibodies, which are more targeted against a specific kind of pathogen, but they take longer to make.
We need both to survive infections. But as we get older, research suggests that our bodies tend to make more cells that launch an innate response, says Matthew Woodruff, an immunology researcher at Emory University in Georgia. Innate immune cells include things like macrophages, some of which sit in areas like the lungs on a stakeout for pathogens. “If they find something they release inflammatory signals,” says Woodruff.
If a virus, like SARS-CoV-2, overwhelms these macrophages, inflammatory fluid can leak into the lungs, which contributes to a dangerous immune response called acute respiratory distress syndrome, or ARDS. ARDS is the hallmark of a severe Covid-19 case, and is much more common in older adults; it often requires treatment with a ventilator.
As older bodies crank up their ability to make inflammatory innate immune cells, it also winds down the ability to make adaptive immune cells. This is one of the biggest reasons why vaccines may not work as well in older adults; their bodies aren’t as equipped to make protective antibodies.
Even though it seems that Trump has recovered from Covid-19 so far, it’s not yet clear how his immune system might protect him later on. He could still be vulnerable to another Covid-19 infection, or he could be even more susceptible to another kind of infection.
The long, unknown road ahead
In younger adults who’ve recovered from Covid-19, doctors have seen some troubling patterns. Sometimes, symptoms from the illness persist for months after the initial infection, or new ones will pop up.
In these cases, doctors have hypothesized that there are one of two things going on. Perhaps the body healed sloppily after Covid-19, creating a new long-term condition to be managed. Or, perhaps the infection revealed some pre-existing condition the body had been able to cope with before getting sick.
Even with Trump’s high-touch care, which included prompt administration of drugs and vitamins, that’s no guarantee he’s in the clear. He’s still finishing out his treatment; any other conditions that may pop up later likely haven’t reared their heads yet.
“With a known course of the illness, day seven to 10, we get really concerned about the inflammatory phase, phase two,” White House physician Sean Conley said in a briefing on Saturday, Oct. 3. “Given that we provided some of these advanced therapies so early on the course a little bit earlier than the most of the patients we know and follow, it’s hard to tell where he is on that course.”
Conley is right to point out that difference. Most older adults in the US won’t have access to that kind of care—so even if Trump’s recovery continues, it won’t be nearly as easy for others.