The coronavirus variant delta is almost six times less sensitive to antibodies developed in humans who have overcome covid, and up to eight times less sensitive to antibodies generated by vaccines from AstraZeneca or Pfizer.
In addition, it multiplies faster in the cell than other variants. This follows from the latest study published in the journal Nature published by an international team coordinated by scientists from the University of Cambridge, the Italian agency ANSA informed.
These features have enabled the delta variant to become globally dominant within a few months. Variant B.1.617.2 (later called delta) first appeared in India at the end of last year and began to spread more rapidly in the spring of 2021. It currently accounts for up to 99 percent of new cases of SARS-CoV-2 coronavirus infection in Europe and 90 percent on a global scale.
According to scientists, the resistance of the delta to antibodies from vaccines and those after overcoming covide also explains many cases of re-infection. The researchers examined the cases of more than 130 health workers from India, almost all of whom were vaccinated but nevertheless re-infected, mostly with the delta variant. Laboratory research has then shown that the delta variant spike protein has a greater ability to attach to a human cell, allowing infection.
“The lower efficacy of vaccines against the delta variant B.1.617.2, which shows a high ability to escape the immune response, justifies the continuation of measures against the spread of the disease in the post-vaccination period,” the study authors conclude.