Why Getting the Common Cold May Decrease Your Risk of Developing COVID-19

Man in his bathrobe blows his nose.
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  • A new study in Nature Communications looked at people who were exposed to the coronavirus early on during the pandemic.
  • They found people with certain T-cells appeared less likely to develop COVID-19.
  • These T-cells are likely made after a person develops the common cold.

People who have recovered from the common cold may be significantly less likely to develop COVID-19, according to a new study.

The study was published January 10 in Nature Communications and looked at people who were exposed to the coronavirus early on during the pandemic.

They found people, who had certain types of T-cells that were likely created after having a common cold, were less likely to develop COVID-19.

“Findings of the study suggest that the immune response spurred by prior exposure to common cold viruses may protect against COVID-19,” Dr. Robert Glatter, an emergency physician at Lenox Hill Hospital in New York, told Healthline.

Researchers believe these findings could provide the “blueprint” for a universal vaccine that might prevent infection from current and future variants.

Participants all lived with someone who had COVID-19

Researchers at Imperial College, London began the study in September 2020 when most of the U.K. hadn’t been infected, or vaccinated, against COVID-19.

The study included 52 people who lived with someone experiencing a PCR-confirmed infection. Participants were given PCR tests at the start, and then 4 and 7 days later, to find out if they also became infected.

All participants provided blood samples within 1 to 6 days of exposure. This enabled scientists to analyze existing levels of immune system T-cells produced from a previous cold, which also recognized proteins in the pandemic virus.

The study findings indicate that participants who didn’t develop COVID-19 from exposure had higher levels of certain T-cells compared with the 26 who did. According to researchers, this is because those immune cells could target internal proteins of the virus, not just the spike protein on its surface.

According to researchers, COVID-19’s internal proteins are much less subject to the mutations that create new variants.

“The spike protein is under intense immune pressure from vaccine-induced antibody, which drives evolution of vaccine escape mutants,” Professor Ajit Lalvani, the senior author of the study, said in a statement.

“In contrast, the internal proteins targeted by the protective T-cells we identified mutate much less,” he added.

T-cells kill COVID-19 before it spreads

Dr. Eric Cioe-Pena, the director of global health at Staten Island University Hospital, said that T-cells are part of the immune system that produce cell-mediated immunity.

“[This] means that they can go to cells that have been infected by a virus and kill them before the virus has the ability to spread and continue to use the cells’ machinery to make more virus,” he explained.

He emphasized that this doesn’t help prevent infection, but does influence how sick someone becomes, and how quickly they recover.

The study authors said that currently available vaccines do not create an immune response to COVID-19 internal proteins, but that this research may impact how future vaccines are developed.

They also predict that, if used alongside spike protein-targeting vaccines, internal proteins offer a new vaccine target that could provide longer lasting protection. This is because T-cell responses last longer than antibody responses — which decrease within months of vaccination.

“In essence, development of a universal vaccine that creates a robust T-cell response across variants could reduce the necessity of ongoing boosters over the next several years,” Glatter explained.

‘Clearest evidence’ that common cold plays a protective role

According to Lalvani, new vaccines that include these “conserved, internal proteins” could induce a T-cell response that should “protect against current and future SARS-CoV-2 variants.”

“Our study provides the clearest evidence to date that T-cells induced by common cold coronaviruses play a protective role against SARS-CoV-2 infection. These T-cells provide protection by attacking proteins within the virus, rather than the spike protein on its surface,” Lalvani said in a statement.

However, this doesn’t mean that catching a cold is better protection than being vaccinated.

“It does not ensure absolute protection, since the immune response, and specifically T-cell production, among the population is variable and influenced by age and underlying medical conditions,” Glatter said.

“But it suggests that T-cells provide an additional and durable layer of protection — and lasting immunity against SARS-CoV-2,” he continued.

Findings might not change how we fight COVID-19

“I’m not sure this adds much that hasn’t already been thought of in the innovation column against COVID,” Cioe-Pena said.

He pointed out that, while this potentially provides new targets for pharmaceutical and vaccine therapy, he doesn’t think it’s going to change much about how we fight COVID-19.

“Rather, [it] is more of an explanation on why COVID appears to be less severe,” Cioe-Pena noted.

“I think it definitely puts people at ease or perhaps provides an explanation for why Omicron is less severe,” he added.

He admitted he’s “not sure it changes much about how we behave, but it is reassuring.”

The bottom line

New research finds that past exposure to the common cold could offer significant protection against developing COVID-19 from exposure.

Experts say that the immune response from a previous cold creates immune cells that target COVID-19’s internal proteins, rather than the surface “spikes.” This could lead to new, longer lasting vaccines.

They also say this doesn’t mean that catching a cold means you don’t need to get vaccinated, since the protection isn’t strong enough to prevent disease.

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