Long-COVID Found to Have Surprising Connection with Common Cold

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Long-COVID Found to Have Surprising Connection with Common Cold

Long-COVID Found to Have Surprising Connection with Common Cold.

A study suggests that “Long-COVID” may be linked to immune imprinting, where prior exposure to viruses affects responses to new infections.

PASC patients exhibit weaker responses to SARS-CoV-2 but stronger responses to another coronavirus called OC43, which causes the common cold.

This insight could provide guidance for future treatments and risk assessment.

The research has uncovered a potential biomarker to identify high-risk individuals for Long-COVID.

Many individuals infected with SARS-CoV-2, the virus responsible for COVID-19, experience symptom relief within days or weeks.

However, a significant portion continues to experience symptoms for weeks, months, or even years, known as COVID-19 Post-Acute Sequelae (PASC), commonly referred to as “Long COVID.” While several risk factors for PASC have been proposed, the underlying causes and why some people develop it while others do not remain unclear.

Furthermore, PASC may have different pathogenic mechanisms in different individuals.

Some PASC patients exhibit alterations in certain immune responses, suggesting a connection between PASC and immune mechanisms.

PASC is particularly prevalent among individuals with systemic autoimmune rheumatic diseases, such as lupus, where the immune system mistakenly targets the body’s own tissues, causing inflammation.

Up to 45% of rheumatic disease patients who contract SARS-CoV-2 develop PASC.

Long-COVID Found to Have Surprising Connection with Common Cold

Research Findings and Antibody Responses

Funded by the National Institutes of Health (NIH), a research team led by Dr. Zachary Wallace of Massachusetts General Hospital (MGH), Dr. Jeffrey Sparks of Brigham and Women’s Hospital, and Dr. Galit Alter of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard University studied antibody responses in rheumatic disease patients infected with COVID-19. They measured antibody responses to SARS-CoV-2, various other pathogens, and vaccines, comparing the responses of PASC patients and those who did not develop PASC. The research findings were published on September 6, 2023, in the journal “Science Translational Medicine.”

The research team found that individuals with PASC had significantly weaker antibody responses to SARS-CoV-2 compared to those without PASC. However, PASC patients exhibited enhanced responses to another coronavirus called OC43, which is a local virus that can cause common cold-like symptoms. Moreover, the stronger the response to OC43 in PASC patients, the weaker their response to SARS-CoV-2. This suggests that antibodies targeting OC43 may also cross-react with SARS-CoV-2. These patterns were observed in two separate groups of over 40 rheumatic disease patients, with approximately one-third experiencing PASC.

Immune Imprinting and Its Implications

The research findings suggest that PASC may be related to a phenomenon known as immune imprinting, where one’s prior history of infections influences their immune response to new infections. In this case, when someone previously infected with OC43 contracts SARS-CoV-2, their immune system partially relies on antibodies generated during the OC43 infection to recognize SARS-CoV-2. This “recall” response to OC43 leads to an overall less efficient response to SARS-CoV-2. Further research is needed to determine if this weakened immune response is indeed a cause of PASC and how it operates.

Dr. Alter explained, “For viruses, the initial encounter with them influences lifelong immunity. We know that in the case of the flu, prior exposure to viral strains can impact one’s immune response to subsequent strains. This concept may also apply to coronaviruses and could impact the risk of Long-COVID, especially in individuals with rheumatic diseases.”

Whether these findings also apply to individuals without rheumatic diseases remains to be seen. However, in certain cases, these results may help explain the pathogenesis of PASC. They also provide clues for guiding the development of novel treatments. Lastly, they propose a biomarker that can assist in identifying high-risk populations for PASC, enabling them to participate in more targeted clinical trials.