COVID-19 study finds 'broader' antibody response maintains immunity to Omicron reversal
Since the release of the SARS-CoV-2 virus on November 26, researchers have been moving in many directions to gauge the severity of the infection caused by the new variant, but also the likelihood of developing the disease. it is against the existing vaccines.
A study published Monday by the biotech company Vir Biotechnology of Switzerland, in collaboration with multiple research institutes, suggests that some monoclonal antibodies developed to fight COVID-19 may work better when what the researchers say are "relatively neutral" tendencies, meaning they recognize many parts of the mutated virus.
"Interestingly, we found three powerful neutral mAbs that bind to the RBM that are not affected by Omicron mutations," wrote lead author Elisabetta Cameroni of Vir, along with dozens of collaborating authors from the University of Washington in Seattle, Washington University in St. Louis. Louis, the Università di Milano, the Institute of Medical Science in Tokyo, and several other research institutes, in the paper, "Relatively neutral antibodies override the antigenic movement of SARS-CoV-2 Omicron," on posted on a BioarXiv preloaded server.
The authors conclude that antibodies that work "widely," meaning that they recognize parts of the virus that do not change, can be a major weapon against mutations.
The paper has not yet been peer-reviewed so care should be taken in looking at its findings.
Also: The COVID-19 Study finds that some recovered individuals and the vaccine maintain good immicron immunization
Antibodies are one of the most common antiviral bodies. If you have contracted COVID-19 and passed it on, one way you can find out is through an antibody test that shows you have antibodies in your bloodstream, The most common are immunoglobulin G, or "IgG."
Drug companies make a type of antibodies called monoclonal antibodies that may be specific in their target virus or other pathogen - a specific target, or "epitope," as it is called.
The element of Omicron that has struck researchers is how far it has gone against the previous four layers of the virus. In particular, the spike protein, where the "receptor binding domain" resides, has undergone more than thirty mutations from its form in previous changes.
Such proliferation of mutations could lead to what is known as "immune escape," as not only is the virus more susceptible but it is better able to respond to antibodies. avoid.
Since its inception, Omicron has caused a panic due to its speed of release.
The U.S. Centers for Disease Control announced Monday that Omicron now accounts for 73% of U.S. cases of SARS-CoV-2, up from 13%. That pace has exceeded CDC expectations, according to Financial Times's Peter Wells and Kiran Stacey.
RBD is the main target for antibodies that can block the activity of the virus, so scientists are trying to determine the extent to which the mutations allow the virus to escape. From the neutral effects of antibodies.
In Vir's study, the scientists advanced in several stages.
They first tested the blood serum of both recovered individuals and the vaccines, covering all subjects representing the major vaccines available, including the Moderna " mRNA-1273, "the Pfizer / BioNtech" BNT162b2 "and the AstraZeneca" AZD1222. "
The researchers identified a general loss of immunity in both those who received the vaccine and those who received the vaccine, including some who did not have an immune response, and some who showed an increased immune response. to 44 times less power.
Interestingly, the scientists note that there was an “extended” immune response to those who had both received COVID-19 and also received the vaccine.
That reveals the results of a study released this week by researchers at the Karolinska Institute in Stockholm.
As the authors write,
Interestingly, this decrease was less pronounced for previously infected (5-fold) vaccinated individuals, consistent with an increase in antibody responses due to maturation-driven antigenic multimodality-induced maturation. .
Next, they tested the action of 44 different monoclonal antibodies against Omicron in vitro, meaning, in the laboratory, not in human subjects. The researchers described a "pseudovirus" of Omicron, a laboratory-prepared form of extraction from "seed" cells, a process known as pseudotyping vesicular stomatitis virus (VSV) that is common in study of pathogens.
Up against the synthesized viral components, they tested eight monoclonal antibodies that are "currently authorized or approved." They noticed that only one of the monoclonal antibodies maintained any efficacy, called sotrovimab. It is interesting to note that it does not target the RBD in the spike protein. Instead, it works by "targeting non-RBM epitopes that are distributed across many sarbecoviruses, including SARS-CoV."
The authors then tested a further 36 monoclonal antibodies. Most of these failed, but three in particular maintained "strong neutral action against Omicron." Two more "reserved action against Omicron," they write.
The key is that all six, including sotrovimab, target non-altering parts of the RBD. “These mAbs identify four antigenic sites in the RBD that are retained in Omicron and other sarbecoviruses,” they write.
The outlook is, the authors write, "Together, these data may guide future efforts to develop SARS-CoV-2 vaccines and treatments to combat transmission. antigenic and zoonotic overdose of future sarbecovirus. "