Moscow. September 7. INTERFAX.RU – Scientists in Great Britain and India have evaluated the ability of the delta variant of SARS-CoV-2, which has become the dominant strain in different countries, to avoid neutralizing antibodies. The researchers found that the delta strain was 5.7 times less sensitive to sera from previously infected individuals and eight times less sensitive to vaccine sera than the alpha variant. This is stated in the message of the University of Cambridge.
“By combining laboratory experiments and the epidemiology of vaccine breakthrough infections, we have shown that the delta variant multiplies and spreads better than other commonly observed variants. There is also evidence that neutralizing antibodies produced by previous infection or vaccination are less effective in stopping that option, “said study co-author Professor Ravi Gupta of the Cambridge Institute for Therapeutic Immunology and Infectious Diseases at the University of Cambridge.
He also noted that in India in the first quarter of 2021, up to half of the cases of COVID-19 were detected in people who had been infected with the earlier variant in the past.
Scientists extracted serum from blood samples from people who had previously been infected with the coronavirus or vaccinated with Oxford / AstraZeneca and Pfizer vaccines.
“The team found that the delta variant virus was 5.7 times less sensitive to sera from previously infected individuals and eight times less sensitive to vaccine sera than the alpha variant – in other words, eight times more antibodies are required to block the virus. from a vaccinated person, “the publication says.
An analysis of more than 100 infected healthcare workers in three hospitals in Delhi, almost all of whom were vaccinated, showed that the delta variant is transmitted between vaccinated individuals to a greater extent than the alpha variant.
Using 3D airway organelles – “mini-organs” grown from airway cells that mimic their behavior, the team studied what happens when the virus reaches the airways.
The scientists used both a live virus and a “pseudotyped virus” – a synthetic form of the virus that mimicked key mutations in the Delta variant – and used it to infect organelles.
“They found that the delta variant was more effective at penetrating cells compared to other variants because it had more split spines on its surface. Once inside the cells, this variant was also more capable of reproducing,” the publication notes.
