Since the common cold is a type of coronavirus, bearing many of the same features and attributes as the novel coronavirus, experts say that many people's immune systems have already been "trained" to ward off infection without the need for pharmaceutical drugs or vaccines.
"Your immune system's 'memory' T cells keep track of the viruses they have seen before," researchers at LJI explain. "This immune cell memory gives the cells a head start in recognizing and fighting off repeat invaders."
Published Aug. 4 in the journal Science, the LJI study breaks down the science behind how the immune system learns about diseases after being exposed to them. If a strong T cell response occurs in response to the common cold, it found, then the immune system is already primed to handle exposure to the Wuhan coronavirus (COVID-19).
"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," says Daniela Weiskopf, PhD, a research assistant professor at LJI who helped co-lead the new research alongside professor Alessandro Sette, Dr. Biol. Sci.
"This could help explain why some people show milder symptoms of disease while others get severely sick."
Earlier research published in the journal Cell showed that between 40 and 60 percent of people who were never exposed to SARS-CoV-2, also known as the Wuhan coronavirus (COVID-19), still had T cells that reacted to the virus, presumably from previous cold infections.
"Their immune systems recognized fragments of the virus it had never seen before," LJI reports. "This finding turned out to be a global phenomenon and was reported in people from the Netherlands, Germany, the United Kingdom and Singapore."
For the new study, researchers specifically evaluated a set of samples collected from participants who had never been exposed to the Wuhan coronavirus (COVID-19). They looked at the exact sites of the virus that are responsible for what they describe as the cross-reactive T cell response.
What they determined is that unexposed people can still produce a variety of memory T cells that are equally reactive against not just the Wuhan coronavirus (COVID-19) but also four other types of common cold coronaviruses, or what Sette describes as COVID-19's "less dangerous cousins."
"Immune reactivity may translate to different degrees of protection," Sette says. "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."
"We knew there was pre-existing reactivity, and this study provides very strong direct molecular evidence that memory T cells can 'see' sequences that are very similar between common cold coronaviruses and SARS-CoV-2," he adds.
Amazingly, some of the cross-reactive T cells that are produced due to immune system exposure to common cold viruses also target the infamous Wuhan coronavirus (COVID-19) "spike protein," which is depicted in most of the 3-D images associated with the pandemic.
Conversely, this is why flu shots are a really bad thing because they directly interfere with the body's innate immune response to pathogenic exposure. Getting jabbed, in other words, impedes the immune system's ability to adapt its response to novel viruses, which in the case of the Wuhan coronavirus (COVID-19) bears many similarities to the common cold. (RELATED: Learn more about flu shots and how they affected the 1918 Influenza Pandemic.)
More related news stories about the Wuhan coronavirus (COVID-19) are available at Pandemic.news.
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