Corona mutations from South Africa and England are causing concern for virologists and doctors. Their infection rate is higher, and whether the vaccines developed are also effective against the variants has not been proven. A team of US researchers has developed a method that can be used to identify which mutations bypass immune protection, as reported by the “Aerzteblatt”.
The discovery was described in the journal “Science”. Some of the mutations being investigated may already be floating around in different countries and bypassing the immune protection of antibody drugs. The extent to which the vaccines lose their effectiveness against the mutations is not described in the study.
The virus’ receptor binding site is an important point of attack for the immune system. Antibodies can thus prevent the virus from penetrating the cells and stop the pathogen. Antibody drugs target these receptor binding sites on the coronavirus spike protein.
Such special corona agents are not yet approved in the EU. It looks different in the USA. Donald Trump was also treated there with the medication during his infection. They promise to weaken the course of the disease. The federal government has already ordered 200,000 doses of two antibody products for 400 million euros.
However, the effectiveness of the antibody drugs can be limited by mutations in the binding sites of the virus. The researchers at the Cancer Research Center in Seattle have now developed a method to examine the effects of various mutations on the ability of antibodies to bind.
Mutations evade immune protection
Accordingly, 2,034 different mutations were examined in the study. A mutation was discovered that would render the US antibody cocktail REGN-COV2 from the manufacturer Regeneron ineffective. The antibody agent was also ordered by the federal government.
In a US patient, the researchers were able to identify four of the mutations discovered that elude immune protection. The patient was chronically infected with the virus due to an immunodeficiency and was ill for a particularly long time, which allowed the mutations to develop over a period of 145 days. Despite treatment with Regeneron’s drug, the patient died shortly afterwards from the effects of the infection.
In a database that stores all of the coronavirus genomes sequenced to date, the researchers were able to determine more of the so-called escape mutations. This also included a mutation that played a role in the corona outbreak among the mink population in Denmark. According to the study results, the mutation K417N, which was detected in the South African pathogen B.1.351, could also evade the antibodies.