A history of seasonal colds could boost your chances of having mild COVID-19 case: study – OregonLive

If you tend to get a cold every winter, you might be in luck. That history could mean you’re better prepared to fight off COVID-19 than people who typically swagger through the dreary months without a sniffle.

A new study published in the peer-reviewed microbiology journal mBio concludes that the novel coronavirus activates memory B immune cells, which might help clear COVID-19. These cells also fight some seasonal colds, and they can survive for decades in the body, biding their time in the background until they’re needed to fight a virus.

The study, which analyzed blood samples from 26 people recovering from mild-to-moderate cases of the novel coronavirus and 21 healthy, non-infected people, is the first to report that memory B cells recognize and react to SARS-CoV-2, or COVID-19.

“When we looked at blood samples from people who were recovering from COVID-19, it looked like many of them had a pre-existing pool of memory B cells that could recognize SARS-CoV-2 and rapidly produce antibodies that could attack it,” the study’s lead author, Dr. Mark Sangster, said in a statement released by the University of Rochester.

Sangster is a research professor of microbiology and immunology at the University of Rochester Medical Center.

New evidence that millions of people have some built-in protection to COVID-19 is good news — and not surprising, seeing as more than 80% of cases produce mild symptoms or none at all. But this limited study does not determine how much past seasonal colds might help a person battle COVID-19.

“What this study doesn’t show is the level of protection provided by cross-reactive memory B cells and how it impacts patient outcomes,” the University of Rochester stated.

The medical center’s researchers will now take up an investigation of whether the existence of “pre-existing memory B cells” in the body can be linked to milder COVID-19 cases or might improve the effectiveness of a COVID-19 vaccine once it becomes available.

The novel coronavirus pandemic has killed more than 200,000 Americans so far this year and more than 1 million people worldwide.

Read the study.

— Douglas Perry

dperry@oregonian.com

@douglasmperry