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Natural medicine: COVID-19 mutants may cause vaccines ineffective
Natural medicine: COVID-19 mutants may cause vaccines ineffective. COVID-19 mutants perform nearly ten times more resistant to vaccine antibodies.
A laboratory study in the journal Nature Medicine warned that the current common new coronavirus mutants are resistant to antibodies, and more antibodies are needed to neutralize these viruses, even up to 10 times.
According to Michael S. Diamond, MD, MD, Washington University School of Medicine in St. Louis, the new coronavirus enters cells through the S spike protein to cause infection, and the infected person also produces protective antibodies against the spike protein. Therefore, the protein has become an antibody drug and vaccine development. Of the target. Pfizer, Moderna, and Johnson & Johnson vaccines marketed in the United States all target this target.
From the winter of 2020, fast-spreading mutant viruses have been discovered in the United Kingdom, South Africa, Brazil and other regions. The most threatening ones are B.1.1.7 (from the United Kingdom), B.1.135 (from South Africa) and B.1.1.248. (From Brazil). The spike protein genes of this type of virus contain multiple mutations, which may reduce the effectiveness of targeted drugs and vaccines currently used for prevention or treatment.
In order to evaluate the resistance of the new mutant virus to antibodies, the Diamond research group tested the neutralizing ability of the antibodies against the mutations of the three viruses in a laboratory environment. They extracted virus antibodies from people who have recovered from infections and Pfizer vaccinators, and they also extracted antibodies from the blood of mice, hamsters, and monkeys immunized with the vaccine. It was found that the B.1.1.7 mutant virus can be neutralized with an antibody level similar to the original virus, but the other two mutant viruses require 3.5-10 times the antibody to neutralize. At the same time, monoclonal antibody drug testing includes the opposite results of effective and completely ineffective.
Further research found that the resistance of the virus to antibodies can be attributed to the single amino acid E484K mutation of the spike protein, which is found in both B.1.135 and B.1.1.248. B.1.135 is a major virus in the South African epidemic, so the preventive effect of vaccines in clinical studies in South Africa is not as good as that in the United States.
Diamond said the results of this study are very worrying. Some people have been infected or vaccinated. We originally thought that they already had protective antibodies in their bodies to form immunity, but their resistance to new mutant viruses is worrying.
The amount of antibodies produced in each person varies greatly. Some people have very high antibody levels, and they still have sufficient resistance to avoid the threat of new mutant viruses; but some people with weaker resistance, such as the elderly, immune People with low functions have slightly lower levels of antibodies in their bodies. If the level of antibodies needed to effectively fight the virus has increased by 10 times compared with the past, it is likely that this group of people has insufficient amounts of antibodies in their bodies. So, these people who deserve protection most cannot actually be protected effectively.
Diamond said that this is only the result of laboratory research, and the immune effect in real humans is not yet known. Antibodies are not the only protection of the human body against viruses. Other components of the immune system may compensatory increase resistance to viruses. Therefore, the true result needs to be judged over time.
Will there be secondary infections? Will you see the vaccine fail? Hope not, but medical scientists still cannot give up the continuous screening of antibodies and adjust vaccine and antibody treatment strategies to ensure that new mutant viruses can effectively prevent transmission after they appear.
(source:internet, reference only)