Sunday January 24th 2021
Are therapies losing their effectiveness?
Researchers fear reinfection through South Africa mutation
The South African coronavirus variant 501Y.V2 could possibly spread more widely than previously thought. In addition, antibody therapies and vaccines could lose their effectiveness against this type of pathogen. Scientists report on these results in two specialist articles that were not yet peer-reviewed by independent colleagues before publication.
The researchers also write that the mutations could also lead to Covid-19 convalescents being infected a second time with the new variant.
The coronavirus variant 501Y.V2 – also known as B.1.351 – was first discovered in South Africa and has now been detected in numerous countries, including Germany. It is characterized among other things by several mutations that change the so-called spike protein of the virus.
The virus uses this protein to attach itself to the body’s cells and eventually invade them.
Variant attaches itself better to cells in simulation
The more effective binding makes the virus more contagious.
The spike protein is also where the antibodies attack, which the immune system produces after an infection or vaccination or which are administered as part of therapy. With the changes considered, there is a risk that the antibodies will no longer “recognize” the virus, Nelson and colleagues continue.
Antibodies could often not prevent infection
The researchers come to the conclusion that three monoclonal antibodies that are administered in a therapy against a Sars-CoV-2 infection no longer work in the South African variant as a result of the mutations.
In laboratory tests with blood from recovered Covid 19 patients, they found that the antibodies contained in them could not prevent cells from being infected with the South African virus variant in many cases. This result points to an increased risk of reinfection, the scientists write.
Carsten Watzl, Secretary General of the German Society for Immunology, points out that the South African virologists did not examine the blood of vaccinated people: “After a vaccination, there are significantly more antibodies in the blood than most of the former Covid-19 patients Case was. ” Only an examination of the blood of vaccinated patients could clarify whether a vaccine had to be adapted to the new variant or not.
“Data much worse than I expected”
Christian Drosten from the Berlin Charité recently emphasized the importance of T cells in the body’s immune response. “If a virus has a mutation at any point, it does not change the T-cell immunity. In this respect, I do not believe that we have to reckon with a failure of the vaccines,” he said in an interview with the “Spiegel”. A variant that could re-infect recovered Covid 19 patients probably has no advantage in a non-immune population like in Germany.
The se data are significantly worse than I expected and suggest that the vaccines will probably have to be adjusted sooner or later,” he said in an interview with the MDR.