Study: Having Suffered from Common Cold May Help Stave Off COVID-19

Suffering from the common cold could help an individual stave off coronavirus disease because the body’s immune system may use its “memory” from the cold to attack the novel coronavirus, a new study suggests.

Immune cells known as T cells that recognize coronaviruses that cause the common cold also recognize aspects of the Sudden Acute Respiratory Syndrome Coronavirus 2, or SARS-CoV-2 which causes the flu-like COVID-19, including the so-called spike protein that it uses to attach itself to human cells, the study published Tuesday in the journal Science said.

"We have now proven that, in some people, pre-existing T cell memory against common cold coronaviruses can cross-recognize SARS-CoV-2, down to the exact molecular structures," said a co-author of the study, Research Assistant Professor Daniela Weiskopf of the La Jolla Institute of Immunology.

"This could help explain why some people show milder symptoms of disease while others get severely sick."

The study, “Selective and cross-reactive SARS-CoV-2 T cell epitopes in unexposed humans,” followed a study published in the journal Cell that discovered 40 to 60 percent of people never exposed to SARS-CoV-2 had T cells that reacted to the virus and called their theory “highly speculative.”

"Immune reactivity may translate to different degrees of protection," said another co-author of the study, Alessandro Sette, also of the La Jolla Institute. "Having a strong T cell response, or a better T cell response, may give you the opportunity to mount a much quicker and stronger response."

More research is needed, the authors of the study said, mainly because it is not known how much T cells figure into fighting COVID-19.

The most recent study examined blood samples collected from people between 2015 and 2018, more than a year before SARS-CoV-2 emerged from China.

The samples contained T cells that reacted to more than 100 specific sites on SARS-CoV-2. The researchers showed that these T cells also reacted to similar sites on four different coronaviruses that cause common cold infections.