Seasonal Colds Could Offer Protection Against COVI
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Months after the coronavirus sprang onto the global arena and claimed a million lives worldwide, scientists are still scrambling to find a vaccine and ultimately, a cure. At the moment, there are around 40 different coronavirus vaccines in clinical trials, with about 240 vaccines in early development. One such study suggests that we may not even need an external vaccine after all and provides evidence that the seasonal colds you’ve had in the past could offer you protection against COVID-19.
On top of that, such immunity to the coronavirus may last a long time, maybe even your entire life, infectious disease experts at the University of Rochester Medical Center say. The study compared blood samples from two groups: 26 people who were recovering from mild to moderate coronavirus and 21 healthy donors whose samples were collected 6 to 10 years ago, long before they could have been infected by COVID-19.
The researchers measured levels of memory B cells, immune cells that can detect pathogens, create antibodies to destroy them, and remember them for the future. The study, published in mBio, found that SARS-CoV-2, the virus that causes COVID-19, induces memory B cells which can live for decades. Most common coronaviruses result in upper respiratory illnesses, and they each trigger memory B cells into action.
The authors of the study believe that this could mean anyone who has been infected by a common coronavirus, which is almost everyone, may develop some degree of immunity to the coronavirus. “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,” says lead study author Mark Sangster, Ph.D., a research professor of Microbiology and Immunology at URMC.
This is the first study to report cross-reactivity of memory B cells, meaning memory B cells that once neutralized cold-causing coronaviruses recognizing SARS-CoV-2 and springing into action. The cells produce antibodies that attack specific parts of the Spike Protein, a key protein used by the coronavirus to invade human cells. Although the Spike Protein looks and acts a little different in each coronavirus, one of its components dubbed the S2 subunit is the same across all the viruses.
The study found that in beta coronaviruses, a subclass that includes SARS, MERS, SARS-CoV-2 as well as two common colds, memory B cells can’t tell the difference between the Spike S2 subunits of different coronaviruses and attacks indiscriminately.
According to David Topham, PhD., the Marie Curran Wilson and Joseph Chamberlain Wilson, Professor of Microbiology and Immunology at URMC, the next step is to determine the level of protection provided by cross-reactive memory B cells and how it impacts patient outcomes. “Now we need to see if having this pool of pre-existing memory B cells correlates with milder symptoms and shorter disease course, or if it helps boost the effectiveness of COVID-19 vaccines.”
This is research that biomedical sector players like VistaGen Therapeutics Inc. (NASDAQ: VTGN) are likely to follow since it suggests that the COVID-19 problem may not be such a long-term threat as had been originally thought.
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