Is Common Cold Linked to COVID-19 Immunity?

Researchers at La Jolla Institute (LJI) in the US found in a study that certain memory cells in our immune system that recognise some common cold viruses are also capable of recognising the SARS-CoV-2 virus. Similar results were found in a study conducted in Germany in April this year. This goes to suggest that prior encounters with common cold infections might help one develop a nascent immunity to the novel coronavirus.

What the Study Says

According to a Telegraph report, the LJI study proposes that certain memory helper T-cells emerge in our immune system in response to common cold infections and can recognise certain molecular structural sites on SARS-CoV-2.

“This could help explain why some people show milder symptoms of disease while others get severely sick,” said Daniela Weiskopf, Assistant Professor at LJI, in a media release.

“Immune reactivity might translate into different degrees of protection. Having a stronger T cell response or a better T cell response might give you the opportunity to mount a much quicker and stronger response.”

Daniela Weiskopf, Assistant Professor at LJI

An earlier study by German researchers had found T-cells capable of recognising the coronavirus in 35 per cent of healthy individuals who had no prior exposure to exposure to SARS-CoV-2. The cells retain memory of specific structures on certain spike proteins of harmless common cold coronaviruses that show similarity to corresponding spike proteins on SARS-CoV-2.

However, certain LJI scientists have cautioned that this relationship between disease severity and memory T-cells needs to be confirmed through more research.

What Does it Mean?

The results of the study imply that the experience of fighting a common cold coronavirus in the past may teach certain T-cells in the body’s immune system to react to SARS-CoV-2 as well.

Earlier studies have also suggested that human coronaviruses are responsible for almost twenty per cent of the upper respiratory tract infections. Scientists postulate that an average adult typically develops a common cold coronavirus infection every two or three years. According to Andreas Thiel, a senior researcher at Charité – Universitätsmedizin, Berlin, “If we assume these cold viruses are capable of conferring a certain level of immunity against SARS-CoV-2, this would mean people who have had frequent exposure to such infections in the past and who test positive for the cross-reactive T cells should have better protection.”