Antibodies that mimic the COVID-19 virus could explain the side effects of the vaccine

MADRID, 26 Nov. (EUROPA PRESS) –

An article published in The New England Journal of Medicine has presented a possible explanation for the various immune responses to the SARS-CoV-2 virus and vaccines. According to their findings, antibodies that mimic the virus may explain the long-term side effects of the vaccine.

Although vaccines have been instrumental in controlling the pandemic, researchers continue to learn how and how well they work. This is especially important with the emergence of new variants and the rare side effects of vaccines such as allergic reactions, inflammation of the heart (myocarditis), and blood clotting (thrombosis).

Critical questions about the infection itself also remain. About one in four COVID-19 patients have persistent symptoms, even after recovering from the virus. These symptoms, known as persistent COVID-19, and the unwanted side effects of vaccines are believed to be due to the patient’s immune response.

Drawing on classical immunological concepts, researchers William Murphy of the University of California at Davis and Dan Longo, a professor of Medicine at Harvard Medical School, suggest that the immune network theory of Nobel Prize laureate Niels Jerne could offer insights. .

Jerne’s hypothesis details a means for the immune system to regulate antibodies. It describes a cascade in which the immune system initially launches protective antibody responses against an antigen (such as a virus). These same protective antibodies can subsequently trigger a new antibody response towards themselves, leading to their disappearance over time.

These secondary antibodies, called anti-idiotypic antibodies, can bind to and deplete initial protective antibody responses. They have the potential to reflect or act like the original antigen itself. This can lead to adverse effects.

CORONAVIRUS AND IMMUNE SYSTEM

When SARS-CoV-2, the virus that causes COVID-19, enters the body, its spike protein binds to the ACE2 receptor, managing to enter the cell. The immune system responds by producing protective antibodies that bind to the invading virus, blocking or neutralizing its effects.

As a form of down regulation, these protective antibodies can also elicit immune responses with anti-idiotype antibodies. Over time, these anti-idiotypic responses can eliminate the initial protective antibodies and lead to limited efficacy of antibody-based therapies.

“A fascinating aspect of newly formed anti-idiotypic antibodies is that some of their structures can be a mirror image of the original antigen and act like it by binding to the same receptors that the viral antigen binds to. This binding can potentially cause non-actions. desired and pathology, especially in the long term, “explains Murphy.

The authors suggest that anti-idiotype antibodies can potentially target the same ACE2 receptors. By blocking or activating these receptors, they could affect various normal functions of ACE2.

“Given the critical functions and wide distribution of ACE2 receptors in numerous cell types, it would be important to determine whether these regulatory immune responses might be responsible for some of the long-lasting or off-target effects that have been reported. These answers could also explain why these long-term effects can occur long after the viral infection has passed, “says Murphy.

For COVID-19 vaccines, the main antigen used is the SARS-CoV-2 spike protein. According to Murphy and Longo, current research studies on antibody responses to these vaccines focus primarily on the initial protective responses and neutralizing efficacy of the virus, rather than on other long-term issues.

“With the incredible impact of the pandemic and our reliance on vaccines as our primary weapon, there is an immense need for more basic scientific research to understand the complex immune pathways at play. This need follows what is needed to maintain protective responses, as well as the potential unwanted side effects of both infection and different types of SARS-CoV-2 vaccines, especially when booster is applied now. The good news is that these are verifiable issues that can be partially addressed in the laboratory and, in fact, they have been used with other viral models “, Murphy rivets.