The coronavirus pandemic is one of the most drastic events of the past decades. No other event has had such a long and lasting impact on everyday life as “Sars-CoV-2” has been since February 2020. And the end of the pandemic is not yet in sight. Even if Health Minister Jens Spahn (CDU) pleaded these days for an end to the epidemic emergency, and thus offended health expert Karl Lauterbach (SPD), among others. The great danger in the room: a virus that manages to completely evade the human immune response.
Virology specialists Theodora Hatziioannou (Professor of Research at Rockefeller University) and Paul Bieniasz (Head of the Laboratory for Retrovirology at Rockefeller University) had such a mind game a good year ago, long before the “Delta variant” existed ) began. The two researchers at Rockefeller University in New York City had set themselves the goal of producing a version of the key protein of SARS-CoV-2, which can escape all antibodies that the human body produces as an immune response to the virus. The two wanted to use it to identify parts of the spike protein that primarily attack the immune system. This makes it possible to understand an important part of the body’s defense against the virus.
“Hybrid Immunity”: How to achieve “Super Immunity”
The researchers mixed potentially important mutations with viruses to test their spikes. However, they only used non-contagious SARS-Cov-2 viruses that can no longer cause disease. The researchers published their results in a study which was published in the journal Nature in September 2021. They report on a spike mutant that underwent around 20 changes and was therefore completely resistant to antibodies produced by the people tested. Both in vaccinated and recovered patients.
“So it is possible that the virus will develop further and escape most of our antibodies, but the genetic barrier to this is quite high,” commented researcher Paul Bieniasz on the result. There was one exception, however: the patients who had recovered from COVID-19 prior to a vaccination had special antibodies that even act against the super virus and were able to neutralize the cultivated spike mutation. The immunity of people who have recovered from COVID in the past year and later with mRNA vaccines are impressively broad“, explains Paul Bieniasz.” This shows us that the natural infection or the vaccines lead to immunity, but in no way exhaust the human immune system’s ability to fight off this virus. “
According to the researchers, people who have had both an illness and a vaccination had an above-average number of strong antibodies. The research team at Rockefeller University had already determined in advance that antibodies produced remain in the body for several months after an infection and can develop further. This enables the antibodies to bind to the spike proteins even better. In combination with mRNA vaccines, these antibodies could be further enhanced. According to experts, this development is due to so-called “memory B cells” of the immune system.
Coronavirus Immunity: The Role of Plasmablasts and Memory B Cells
After an infection or vaccination, most of the antibodies come from so-called plasmablasts. However, plasmablasts are very short-lived cells that will die off again as soon as the antibody level drops. After the plasmablasts die, all antibodies come from the much rarer memory B cells. They are then the main source of antibodies. “Some of the memory B cells produce higher quality antibodies than plasmablasts“says Michel Nussenzweig, an immunologist at the Rockefeller Institute.” This is because they develop in the so-called lymph nodes and acquire mutations that help them to bind more closely to the spike protein over time. Those cells that have recovered from SARS-CoV-2 and come into contact with the spike protein of the virus would then become these cells activate and produce highly effective antibodies.