The rapid and massive spread of the “delta” strain of coronavirus worldwide can be explained by its increased ability to replicate and reduced sensitivity to neutralizing antibodies. Such conclusions were reached by an international team of scientists whose article was published in the journal Nature.
Researchers from India, together with colleagues from Europe and Japan, compared the characteristics of different variants of SARS-CoV-2. Laboratory experiments have shown that compared to the “Wuhan” variant of the coronavirus, the “delta” strain is six times less sensitive to antibodies of those who have undergone infection and eight times less sensitive to antibodies developed by people after vaccination with Pfizer and AstraZeneca drugs. In human respiratory tract reproducing models and organoids, it was replicated more efficiently than the “alpha” and “kappa” strains. According to scientists, this is due to the split form of the S-protein in the “delta” variant, which allows it to enter the cell more efficiently.
In addition, the researchers studied 130 cases of infection of vaccinated medical workers in three hospitals in Delhi and showed that the AstraZeneca drug is less effective against the “delta” strain than against other variants of the coronavirus.