HOW MANY HIDDEN CASES OF COVID ARE THERE? I have not knowingly suffered from the infection, but is it possible that I have been exposed but not manifested symptoms? Have you, too, never had a COVID infection? Think again. Today we look at “silent COVID.”
A growing body of evidence suggests that millions of us have had COVID-19 infections without knowing it. We had no symptoms or very mild cases that we mistook for allergies or a cold.
Could I be unwittingly fueling the development of novel coronavirus variants? Has my excellent hygiene allowed me to dodge COVID-19? I have certainly been among folks who have tested positive shortly after I had been around them.
Avoiding COVID-19: Superimmunity?
As I think about the possibility that I have had a silent or symptom-free novel coronavirus infection, I wonder whether some of us are genetically more able to fight off the virus.
Do we have a genetic quirk that wards off infection? Do I have super-immunity, good luck, careful risk-reduction strategies, or some combination of these?
A 2020 study reported that 40 to 45 percent of those infected with COVID-19 remain without symptoms. A follow-up analysis of 95 studies came to similar conclusions, estimating that more than 40 percent of COVID-19 infections come without any symptoms.
The rate may be lower, as a meta-analysis of 13 studies including nearly 22,000 people calculated the rate of symptom-free presentation at 17 percent. The researchers defined asymptomatic individuals as having no key COVID-19 symptoms during the entire follow-up. They only included studies following subjects for at least seven days.
The idea of a genetic advantage in fighting off an infection is not incredible. US National Cancer Center immunologist Dr. Mary Carrington helped discover a mutation that makes it impossible for most strains of the AIDS virus (HIV) to enter human cells.
Could something similar be happening to those of us who do not get the virus or get it and suffer only minimal symptoms? Listen to Harvard T.H. Chan School of Public Health infectious disease researcher Stephen Kissler, Ph.D., speaking with Medscape:
“It’s definitely true that some people have had COVID and don’t realize it. It is potentially good news if there’s more immunity in the population than we realize.”
Sidebar: Dr. Carrington thought she might be one with super-immunity against COVID-19, having dodged the virus for two and a half years. Alas, after returning from a trip to Switzerland, the NCI scientist discovered she had COVID.
“It is man’s natural sickness to believe that he possesses the truth.”
― Blaise Pascal
Resisting COVID-19
Writing in The Atlantic, staff writer Katherine J. Wu, Ph.D., offers that researchers are finding some trends with COVID-19. For example, Rockefeller University scientists are discovering the importance of an “alarm-like immune molecule” known as interferon.
Those who rapidly pump out lots of the protein in the hours after exposure to COVID tend to do better. On the other hand, if your interferon responses are suboptimal, you are more likely to get very sick. The same applies to those who make maladaptive antibodies that attack interferon as it passes messages between cells.
Other mechanisms are at play regarding our response to an infection. How well do your cells sense the viral invasion? Our your various defense mechanisms well-coordinated? What about the brakes your immune system puts on itself?
Hopefully, researchers will discover mutations that may change people’s chances of developing long COVID.
As I did the research for this piece, I learned that those on the breast cancer estrogen-blocking drug tamoxifen have a lower risk of getting COVID. Might other approved drugs be repurposed to fight COVID-19?
Thank you for joining me today in this look at “Silent Covid.”
The information I provided in this blog is for educational purposes only and does not substitute for professional medical advice. Please consult a medical professional or healthcare provider if you seek medical advice, diagnoses, or treatment. I am not liable for risks or issues associated with using or acting upon the information in this blog.
