Three new studies led by researchers from Boston-area institutions have delved further into how the body’s immune system responds to SARS-CoV-2, the virus that causes COVID-19.
“If we want to ask more of our immune system, we need to know what it is capable of,” said Dr. Duane Wesemann, associate professor of immunology at Harvard Medical School and a researcher at Brigham and Women’s Hospital’s Division of Allergy and Clinical Immunology.
“If we can understand and tap into what gives some people an immunological edge, we may be able to coax the immune system through improved vaccine strategies to give a little more,” he said in a statement last week from the hospital. Wesemann was one of the senior authors on two of the papers and a coauthor on the third.
The three papers appeared in the journal Science Immunology. The research was led by investigators from the medical school, the Brigham, Massachusetts General Hospital, and the Ragon Institute of MGH, MIT and Harvard, the statement said.
In one study, researchers looked at 73 antibodies made by people who had been infected by the original strain of the coronavirus, first identified in Wuhan, China, to see how they performed against subsequent variants, including Delta and Omicron. Some of the antibodies could neutralize variants, which is consistent with the current vaccines formulated to address the original strain still providing protection against variants, the hospital said.
In a second study, researchers looked at immune recall, the process of summoning memory cells into action to fight a pathogen. The researchers found that people who had been infected and vaccinated as well as people who had been vaccinated and boosted could mount a strong and broad response across variants, including Omicron, the hospital said.
In addition, the hospital said, researchers found that immune memory of common cold coronaviruses might be key to the robust, sustained immune response in a small subset of unvaccinated individuals who swiftly recover from COVID-19.
“We’re very excited about this idea that some people sustain their antibodies and have memory B cells that can react across variants — it raises some interesting possibilities as we think about a pan-coronavirus vaccine,” Wesemann said in the statement.
“Strategies to maximize robust levels of protective antibodies that are stable over time and retain function across mutating variants through vaccination is a vital goal. Understanding the capabilities of the immune system in this regard, and how available vaccines can elicit them is critical both for the ongoing SARS-CoV-2 pandemic as well as for future vaccine strategies more broadly,” the study said.
In the third study, led by Dr. Andrew Luster and James Moon of the Center for Immunology and Inflammatory Diseases and Division of Rheumatology, Allergy and Immunology at MGH, researchers tried to better understand the role of CD4+ T cells, another crucial immune system component, in fighting COVID-19.
Researchers found certain CD4+ T cell subsets were more common in people who had milder COVID-19 and did not require hospitalization. This cellular response appeared to persist for several months, potentially giving the immune system an advantage when confronted again with the coronavirus, including variants, the hospital said.
Luster said in the statement that the study results supported “the general immunological theory that optimal antibody responses require robust CD4+ T cell help and that vaccines should be designed to also maximize responses by this component of the adaptive immune system.”
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