Since the start of the pandemic, some have pondered if past exposure to the common cold, many of which are caused by seasonal coronaviruses, could offer some protection against the novel coronavirus that was identified more than a year ago. But a new study suggests that a past bout with the common cold will do little to protect you from COVID-19.
For the study, conducted by researchers at the Perelman School of Medicine at the University of Pennsylvania and published earlier this month in the journal Cell, researchers examined hundreds of blood samples collected prior to the start of the COVID-19 pandemic, examining them for antibodies to seasonal coronaviruses (CoV).
About 20% of the samples had antibodies to seasonal coronaviruses (CoV) that, in theory, could bind to both cold-causing CoVs but also to "key sites on SARS-CoV-2," the novel coronavirus, the researchers said.
But these antibodies were not able to neutralize the infectivity of SARS-CoV-2, they found, and "were not associated with better outcomes in people who later went on to get COVID-19," according to a news release on the findings.
The researchers also found evidence that common cold antibodies may not spare young children from severe COVID-19, as past hypothesizes have suggested. How often young children are infected and how readily they transmit the virus to others have also been widely debated since the start of the pandemic.
In the study, the researchers found that both adults and children had similar levels of CoV antibodies, "implying that these antibodies are not the factor that confers protection against severe COVID-19 among most children," who have largely avoided severe illness from COVID-19.
"We found that many people possessed antibodies that could bind to SARS-CoV-2 before the pandemic, but these antibodies could not prevent infections," said study leader Scott Hensley, an associate professor of microbiology at the University of Pennsylvania's School of Medicine, in a statement.
Though antibodies from a previous common cold infection do not prevent a COVID-19 infection, Hensley said, "it is possible that pre-existing memory B cells and T cells could potentially provide some level of protection or at least reduce the disease severity of COVID-19."
However, "studies need to be completed to test that hypothesis," he noted.
Speaking to the New York Times, one expert said he was relieved that the study provided evidence against what he called a "persistent urban legend throughout the pandemic" — that a past bout of the sniffles can protect one against COVID-19.
"Hopefully, this new paper will finally cool everyone down and put such thoughts into the freezer," Dr. John Moore, a virologist at Weill Cornell Medicine in New York City, told the paper.