Two years after the first COVID-19 patients sounded the alarm that symptoms could last for months, it’s clear the phenomenon is common – but medical experts still don’t know much about what causes it or how. treat him.
A Centers for Disease Control and Prevention study of 353,000 COVID-19 survivors found that about one in four adults age 65 or older and one in five adults under age 65 have developed a new health condition which could be linked to their fight with the virus.
There isn’t much data on why some people struggle with symptoms months after most COVID-19 patients have recovered, or when they might expect to feel better. , however.
Diagnosing what has become known as long COVID is primarily a process of ruling out anything that might be causing a patient’s symptoms, said Dr. Thomas Campbell, professor of medicine at the School of Medicine. Medicine from the University of Colorado and Director of Clinical Research at UCHealth.
The most common reasons patients visit UCHealth’s long-running COVID clinic are fatigue and respiratory symptoms like a persistent cough or shortness of breath — all symptoms that can have many causes, he said. declared.
“It’s not black and white at all,” Campbell said.
It’s no surprise that people who are sick enough to be treated in an intensive care unit have persistent symptoms of both the medical condition itself and the measures needed to save their life, such as spending time on a fan. Other viruses can also cause prolonged symptoms in mildly ill people, but the phenomenon is more common with COVID-19. It is also unusual to see so many different symptoms.
It still appears that women are more likely to have long COVID, but it’s possible this reflects differences in care-seeking, Campbell said. Data from the UK found the same gender difference, although US and UK studies disagree on whether the risk increases with age or peaks between ages 50 and 69. . The UK data did not include people living in care homes, which may have caused it. underestimating the number of people over 70 affected.
For now, treatment still focuses on addressing specific symptoms, such as giving patients medication to reduce coughing and gradually building strength and endurance through physical therapy, Campbell said. Most patients start feeling better within three or four months, but people who were in poorer health before contracting the virus or who became seriously ill from the virus may take longer, he said. declared.
There’s always a process of trial and error for drugs, but evidence seems to be mounting for a process of extremely slowly increasing people’s activity levels, said Dr Tod Olin, director of Exercise and Performance Breathing Center at National Jewish Health in Denver. It’s boring for people used to more intense exercise, but overdoing it seems to wipe out much of the progress patients have made, he said.
The National Institutes of Health recently launched a study, called RECOVER, to understand why some people develop long COVID symptoms and others don’t, Campbell said. People who have had COVID-19 and want to participate can email [email protected]
“To deal effectively with long COVID, we need to understand it,” he said. “Otherwise, these are just guesses.”
One cause or several?
Olin said he and his colleagues observed three general types of long COVID patients: people with excessive fatigue and shortness of breath; those whose heart rate increases erratically, making them dizzy with even light activity; and those with “brain fog.”
There are many other post-COVID symptoms, but these are usually the ones that cause people to seek treatment, he said.
It’s too early to know if these are three presentations of one disorder or separate syndromes with different underlying causes, Olin said.
CDC researchers looked at 26 conditions affecting the heart, lungs, kidneys, blood vessels, digestive system, brain, and muscular system. While the risk for almost all conditions was higher in people who had had COVID-19, the odds of developing a new respiratory disease were particularly high.
The study did not prove that the virus caused all of these conditions, as it is possible that doctors were looking more closely for other problems in patients who had had COVID-19, or that some people had a condition before contracting the virus and were not diagnosed until after.
Some researchers believe the long COVID could be caused by an immune response gone awry, while others think fragments of the virus could be lurking somewhere in the body, keeping it in a chronic state of inflammation. Some believe that both could be correct and that some patients may have another underlying problem.
The National Jewish researchers also found that in patients reporting excessive fatigue, cells did not seem to use available energy well. It’s an intriguing finding, as they typically only see this pattern in people with certain rare diseases, but it’s far too early to say that’s what’s causing long COVID, Olin said.
“It’s a really preliminary signal,” he said.
Vaccines help – but how much?
A study of people treated by the US Department of Veterans Affairs found that those who had been vaccinated and had a breakthrough infection still had an increased risk of multiple health problems, compared to those who did not have COVID. -19.
They were better off than people who hadn’t been vaccinated before getting sick, with about a 15% lower risk of post-COVID symptoms – less protection than previous studies had suggested for vaccinated people.
Like the CDC effort, the VA study was conducted before omicron took over and before booster shots became widespread, which may affect the results.
Dr. Zizad Al-Aly, head of research and development at the VA St. Louis Health Care System, said it’s not entirely surprising that vaccinated people aren’t completely protected, because the vaccines have been developed to prevent serious illness and death. Asking vaccines to prevent a different syndrome is like expecting someone who has trained for years as a sprinter to excel in a marathon, he said.
“They were never designed to protect us from a long COVID,” he said.
Benefits were greater for certain conditions. Vaccinated people were about half as likely to develop blood clotting disorders as those who were not vaccinated, and their risks of serious lung problems were also significantly lower, Al-Aly said. It’s not entirely clear why the level of protection is different, but it could indicate that vaccinated people are less likely to develop severe COVID-19, which involves lung damage and abnormal clotting, a- he declared.
“It may be a carryover effect,” he said.
Not everyone is convinced that the benefits are so modest. Other studies have shown that vaccination provides more protection against long COVID, with estimates ranging from a 50% to 60% reduction in risk, Campbell said. The people who receive their care at VA clinics are not the same as the general population, he noted.
“The VA is a predominantly male patient population, and not necessarily representative,” he said.
There isn’t enough data yet to know whether reinfections carry the same COVID risk as a first bout with the virus, but Al-Aly said he suspects any protection from prior infection would prove modest. , if it exists. . If true, that would pose a major problem, as nearly everyone will eventually become infected, he said, and some will contract the virus multiple times.
Other than getting vaccinated, the only way to prevent long COVID at this point is to not catch the virus in the first place. It won’t be a viable plan for most people because the virus is going to be with us for the foreseeable future, Al-Aly said.
The country needs a strategy to prevent long COVID, whether it’s vaccines specifically designed to ward off those symptoms or treatments that can drastically reduce the odds, he said.
“It’s very difficult to keep dodging,” he said.
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