Since the advent of new COVID-19 variants, experts have worried that the virus may have developed mutations that make it possible to maneuver existing vaccines.
Early laboratory studies proved worrying and showed that vaccines appeared to produce far fewer antiviral antibodies against some of the newer variants. But the real experience did not respond to these concerns – people seemed to develop good protection even when exposed to new varieties.
After months of research, vaccine experts across the globe are learning that vaccines still work best – even when these antibodies are not shown in large numbers ̵
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“One of the reasons the vaccines stop using variants is that they raise a wide range of immune responses,” says Dr. Dan Barouch, Director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center. “We speculate that several immune parameters may contribute to the protection observed by this vaccine against variants.”
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In a recent study, Barouch and some colleagues showed that the Johnson & Johnson vaccine made all different parts of the immune system respond. Crucial to the fact that the study helped strengthen the importance of so-called “kills” T cells in the defense against viral variants, including the worrying “Beta” variant that was first identified in South America.
“Killing T cells is important because they can actually identify an infected cell and get rid of it, and so they are very good at collecting the infection,” says Dr. Paul Goepfert, Professor of Medicine at the University of Alabama at Birmingham. and an expert in vaccine design.
The body’s ability to utilize several parts of the immune system after immunization against the original strain of COVID-19 still leads to robust protection against several variants.
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Back in December, when news first surfaced of a troubling variant in the UK now called the Alpha variant, some vaccine experts were concerned that the new version of the virus might sign vaccines.
The news was even more disturbing as vaccines were currently only approved. In the following weeks, the world learned about the Beta variant from South Africa and the Gamma variant from Brazil.
Vaccine companies began preparing to test new booster shots specifically targeting these variants, but in the real world, vaccines still seemed to offer relatively good protection to people living in countries where new variants were prevalent.
Barouch’s new research provides some clues as to why.
The human immune system consists of several components that help fight viral infections by producing antibodies, a protein created to neutralize foreign objects, and also seek out infections, destroy them and remember them so that it can fight better and faster next walk.
Like previous studies, this study showed that the variants have mutations that are not well recognized by the antibodies generated after vaccination or infection. In fact, antibody levels from the J&J vaccine were 5.0-fold lower against the COVID-19 Beta variant first identified in South Africa and 3.3-fold lower against the Gamma variant first identified in Brazil, which similar to that seen in other vaccines.
But antibodies do not tell the whole story.
“We do not necessarily trust the amount of antibody in our blood at the time we are exposed to something to protect ourselves,” said Dr. Anna Durbin, an infectious disease physician and professor of global disease epidemiology and control at Johns Hopkins. . “We have a memory immune response, so when we see it pathogenic again, our body produces more antibody, produces T cells in response to it. It really gears up to control this infection.”
So even with fewer antibodies produced, other parts of the immune system are ready to recognize and fight the infection, she added. And even if a vaccinated person becomes infected, the severity of the disease is likely to be blunted.
“The J&J vaccine induces really good Killer T cell responses, and even though they may get infected, these Killer T cell response can help get rid of this infection very, very quickly,” Goepfert said.
Actual data quoted by Durbin show that vaccination provides “… really excellent protection against severe adherent COVID caused by the variants, and I think it’s probably due to the memory immune response we have and the T cell response we have. has, it is able to clear that virus if we are infected. “
Onyema Okolo, MD, an oncologist and hematologist from the University of Arizona Cancer Center in Tucson, is a contributor to the ABC News Medical Unit.
We know that vaccines work against new COVID variants. Now researchers are beginning to understand why. originally appeared abcnews.go.com