Written by Elisia Leung, Edited by Maura McDonagh, Justin Nguyen, and Courtney Coleman
The rise of new SARS-CoV-2 mutations, such as the delta variant, has been an alarming concern for everyone. Many people think that these mutations make it harder for the world to ever recover; however, our immune systems are more capable of fighting off these mutations than some might think. For people who have already been exposed to SARS-CoV-2, researchers have found that our immune systems, which “remember” past infections, have the ability to adapt and change in order to better fight the virus.
How does the immune system do this? Well, after a patient has been infected with COVID, the body maintains “reserve armies” of antibody-producing cells, called B cells, in addition to the first cells, such as macrophages and neutrophils, that responded to the initial invasion by SARS-CoV-2. Additionally, the immune system has B cells that mix and match segments of genes that encode antibodies in order to generate millions of unique combinations. During this process, B cells will splice out segments of the genes from the DNA to create three regions (variable, diverse, and joining regions). It is estimated that, given the number of variants in each of the three regions, approximately 10,000-20,000 unique antibodies are producible. As a result, over time, many antibodies are better able to recognize new viral versions and better recognize and fight off COVID infections.
In research done by scientists at Rockefeller University, scientists cloned reserve B cells in order to test them against a modified mutation of Covid that has similar spike proteins, which are proteins that allow viruses to penetrate host cells and cause infection. This experimental mutation was safe to use in the lab because it lacked the ability to replicate, and thus could not infect researchers or be spread. The mutations mimicked a few of the ones currently found in the variants of concern, such as B.1.351. When the researchers tested these reserve cells against this mutated virus, they found out that the cells did bind to the mutated spike proteins, despite it being different from the original spike pattern from the Covid it once fought. What this means is that the antibodies had changed over time in order to recognize different viral features. In other research led by Dr. Ian Wilson at the Scripps Research Institute, scientists discovered that antibodies were able to bind to the spike of the protein despite the antibodies being out of the receptor binding site. As a result, the antibodies were still effective against other variations of the virus.
From these two experiments, there is evidence that our immune systems are more capable of recognizing, and defeating, new SARS-CoV-2 variants versus the novel virus humans first encountered in 2019. With scientists gaining more knowledge about how our bodies react to mutations, the rise of booster shots, and stronger Covid preventive actions, our society is on the right path to defeating SARS-CoV-2 and all its variants.
This post is not a substitute for professional advice. If you believe that you may be experiencing the symptoms of COVID-19, please contact your primary care physician, or go to the nearest Emergency Room. Results from ongoing research and the current understanding of COVID-19 are constantly evolving. This post contains information that was last updated on April 20, 2023.