
PASC stands for post-acute sequelae of COVID-19 infection. Debilitating symptoms such as fatigue, brain fog and shortness of breath are common after COVID. They have been puzzling doctors for a long time. While other viral infections occasionally trigger lingering health problems, these appear to be far more common with COVID. No one knows why some people suffer from long COVID and others seemingly get better. Could the coronavirus persist in hidden places within the body after initial recovery? Might it be triggering long-lasting symptoms that go unrecognized?
How Many People Caught COVID-19?
The experts are suggesting that over 100 million Americans had confirmed cases of COVID-19. Confirmed refers to cases that were verified by a laboratory. When it comes to probable cases, it’s anyone’s guess. I have seen numbers around 150,000,000.
Please keep in mind that the COVID Tracking Project stopped collecting data in March, 2021. It is entirely possible that over 200 million people caught COVID at least once. Many caught it multiple times. And we have no idea how many people caught SARS-CoV-2 and didn’t even know it. Whatever the number actually is, the total number of COVID cases is immense. How many are experiencing symptoms from long COVID is even more obscure.
What Are the Symptoms from Long COVID?
According to some very smart people who have studied this question in depth (Nature Reviews Microbiology, March, 2023):
“More than 200 symptoms have been identified with impacts on multiple organ systems.”
I will not list them all in this post. Here are just a few of the most common complaints according to the CDC (July 24, 2025):
- Tiredness or fatigue
- Symptoms that get worse after physical or mental effort
- Heart palpitations
- Difficulty concentrating (brain fog)
- Headaches
- Sleep problems
- Dizziness, especially upon standing
- Anxiety or depression
- Digestive disorders (diarrhea, stomach pain, constipation)
- Joint pain
A lot of people are experiencing sleep problems these days. And given the headlines, it’s hardly surprising that many people are experiencing anxiety or depression. Judging from our email, a lot of folks also complain of fatigue and brain fog.
Are such symptoms “normal” or are they lingering complications of long COVID? No health professional can answer that question. And remember, many people may have caught SARS-CoV-2 without actually knowing it. Some are still catching it today. Relatively few people are testing for COVID-19. Could there be lingering aftereffects of this infection that have gone unrecognized?
Modern Medicine Has Failed the Fatigued!
I recently reviewed the tragic history of chronic fatigue syndrome CFS). That’s because we were among the first medical journalists to interview Paul Cheney, MD, PhD on our radio show in 1988. You can read all about Dr. Cheney and why “CFS was the Canary in the Coal Mine” at this link:
“How Medicine Keeps Failing the Fatigued: CFS, Long COVID and Long Vax”
Infectious disease experts downplayed the idea of ME/CFS (myalgic encephalomyelitis/chronic fatigue syndrome) for far too long. “Long Lyme” has also been discounted, though one of the country’s leading experts suggests that anywhere from 15% to 20% of people who catch Borrelia burgdorferi may not get over this infection even after a “standard” course of doxycycline. You can listen to our interview with Dr. John Aucott at this link.
New Research Suggests the Coronavirus Persists in the Body:
Many healthcare professionals have been taught that we overcome infections in a relatively short period of time. If you catch a cold, the flu, Lyme disease or COVID, the theory goes that your body mounts a defense and eventually kills off the invading organism(s). That theory could be wrong!
A study published in PLoS Pathology, July 24, 2025 concludes that:
“…PASC may be more prevalent than estimated from self-reported symptoms in human studies.”
This research demonstrates that even mild infections can lead to symptoms many weeks or months later. Researchers at Oregon Health & Science University studied rhesus macaques. Even though they were unvaccinated, the animals did not become very sick when they were infected with COVID-19, and they recovered promptly. But six months later, many of them had signs of chronic illness.
The scientists studied these primates because they react much as humans do. They noted that there was evidence of persistent viral RNA in nose and mouth tissues as well as stool, indicating persistent infection of the digestive tract.
The monkeys had elevated markers of inflammation and hormones indicative of diabetes and heart disease. In addition, many were not sleeping well. All of the animals showed signs of changes following infection, but those that were obese fared worse. Specifically, they had persistent lung pathology even if they were not having trouble breathing.
The investigators conclude that their study:
“suggests that the true prevalence of PASC in the human population may be significantly underestimated.”
How Could the Coronavirus Persist in the Gut?
Harvard scientists announced that they found proteins from the SARS-CoV-2 virus in many patients’ blood as long as a year after the first diagnosis (medRxiv, June 16, 2022). The spike proteins they identified don’t usually last very long in blood, indicating that the body harbors active virus shedding bits and pieces. About 65% of those with long COVID had such proteins in their blood, while people with no persistent symptoms did not have evidence of viral proteins.
The authors of this study suggest that
“The presence of circulating spike supports the hypothesis that a reservoir of active virus persists in the body.”
What Does It Mean If the Microbes That Cause Coronavirus Persist?
Infectious disease experts like short-lived microbes. If a patient has pneumonia and a doctor prescribes penicillin, the infection should clear within a week or so. An ear or urinary tract infection usually gets better within three or four days after appropriate antibiotic treatment.
Some infections are harder to eradicate, though. Chronic Lyme disease is especially problematic. It can take months to overcome and some people have a much more challenging time of it. Tuberculosis can take six to nine months to wipe out. The virus that causes hepatitis C can take two to six months to cure with antiviral medication. And the virus that causes chicken pox (varicella-zoster) can linger in the body for many decades before it is reactivated and triggers a shingles attack.
If Coronavirus Persist, Does That Lead to Long COVID?
Most infectious disease experts assume that once the immune system kicks in after a COVID infection, the virus is cleared from the body. The belief is that within a week or two, people are no longer infectious, and the virus has been wiped out.
But the Harvard researchers previously detected viral RNA from COVID-19 in stool samples of children with persistent symptoms. Other scientists have also found evidence that the SARS-CoV-2 virus may linger in the digestive tract for months or longer. This is especially true when these patients suffer long-lasting GI symptoms.
What Does the Future Hold?
The Harvard researchers summarize their research:
“In conclusion, the presence of circulating spike in PASC patients up to 12 months post-diagnosis strongly suggests that SARS-CoV-2 viral reservoirs persist in the body. Additionally, the detection of spike in a majority of individuals included in our PASC cohort provides strong support for the use of spike as a biomarker for PASC. If PASC patients can be identified based on the direct measurement of spike protein, characterizing patient phenotypes and assessing treatment strategies will become increasingly effective.”
Researchers are investigating the possibility that a variety of antiviral treatments might help eliminate any residual virus and help clear symptoms of long COVID. That is still hopeful conjecture. Much research needs to be done to overcome long COVID. Millions are suffering!
We do not understand why our government is not spending an adequate amount on research to 1) better understand why so many people are still suffering from long COVID and 2) how to treat this condition effectively!
Final Words:
What do you think? Did you catch COVID? Did you completely recover? Are you experiencing symptoms such as sleeping difficulties, bouts of brain fog, tiredness or joint pain? Are they “just” signs of aging or could they be something more insidious? Please share your experience in the comment section below.
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Citations
- Sauter, K.A., et al, "Effect of obesity on the acute response to SARS-CoV-2 infection and development of post-acute sequelae of COVID-19 (PASC) in nonhuman primates," PLoS Pathology, July 24, 2025, doi: 10.1371/journal.ppat.1012988
- Davis, H.E., et al, "Long COVID: major findings, mechanisms and recommendations," Nature Reviews Microbiology, March, 2023, doi: 10.1038/s41579-022-00846-2