Cells Exposed to Common Cold Enhance Immune Response to SARS-CoV-2

Immune cells found in individuals previously exposed to common cold coronaviruses enhance the body’s immune response to SARS-CoV-2, during both natural infection and vaccination, the results of a new study show.

“During infections with the more harmless coronaviruses, the immune system builds up a kind of protective 'universal coronavirus' memory,” Claudia Giesecke-Thiel, MD, Head of the Flow Cytometry Service Group at the MPIMG, said in a statement.

"Once exposed to SARS-CoV-2, these memory cells are reactivated and kick-start the response against the new pathogen. This could help accelerate the initial immune response to SARS-CoV-2 and limit viral propagation during the early stages of the infection and is therefore likely to have a positive effect on the course of the disease."

The data confirm that T helper cells generated memory capability to deal with harmless common cold coronaviruses, which will also attack structural similar coronaviruses, such as SARS-CoV-2. This cross-reactive immunity could be a reason that there is a severity difference among individuals and may show why vaccine efficacy varies among age groups.

The quality of the immune response was linked to the quality of cross-reactive cells that were present in the individual before infection.

“Infection with an endemic coronavirus represents a benefit in younger people, helping them fight off SARS-CoV-2 or develop immunity following vaccination. Sadly, this benefit is less pronounced in older adults,” Andreas Thiel, an investigator based at a joint research space of Charité and Technische Universität Berlin and the BIH Center for Regenerative Therapies said in the statement. “It is likely that a third [or booster] dose would be able to compensate for this weaker immune response, ensuring that members of this high-risk group have adequate immunity.”

Reference

Prior exposure to common cold coronaviruses enhances immune response to SARS-CoV-2. ScienceDaily. News release. September 2, 2021. Accessed September 3, 2021. https://www.sciencedaily.com/releases/2021/09/210902174754.htm