Study: 90% of new crown infections in Russia in April were caused by the “lucky” delta variant
Scientists from Skoltech and their colleagues studied the genetic makeup of the leading strain of COVID-19, the delta strain. According to their introduction, different from many other countries, there is only one virus subtype in this country, which has quickly become the culprit of the vast majority of cases. The team concluded that this may have occurred entirely by accident, not because the subspecies was more infectious or immune resistant.
The results of the study point out that in the early stage of the new pandemic, every case is very important, and strict travel regulations are an effective response.
At the moment, researchers are monitoring the rise and spread of different COVID-19 subspecies in order to closely monitor the evolving virus.
And early detection of some of the worse mutations it may acquire – those that make it easier to infect people, resist natural or vaccine based immunity, and escape testing tools. Technically, these subspecies are called lineages.
“But a subline may also succeed simply because of its good luck,” commented Georgii bazykin of the kharkevich Institute for information transmission of skoltech and RAS, the main researcher of the study, “Understanding this situation is also important for understanding the epidemic and predicting how it will evolve. This has obviously happened on the delta variant, which dominated the epidemic in Russia from April to October 2021.”
The researchers found that a specific lineage named ay.122 accounted for 85% of all infections in Russia in April 2021, but only 0.5% of cases worldwide. More than 90% of the virus samples analyzed in the study showed a set of obvious mutations, which strongly indicated that they were “imported” from abroad Although genetic evidence also points to several other import events, these events have proved to be relatively unsuccessful.
Neither the transmission of delta virus in most other countries nor the previous transmission of delta virus in Russia has the characteristics of a sub strain dominating the domestic epidemic as revealed in this study. This makes Russia belong to the same group as Singapore, Australia, Britain, Turkey and Japan, that is, the characteristics of delta variant are not seen in these countries On the contrary, countries including Poland, Greece, Romania and the Czech Republic have seen the rise of multiple competitive subsets.
“Although the success of the prevalent subline in Russia obviously has nothing to do with its adaptability, the biggest revelation may be this. Bazykin pointed out,” we can clearly see that in the early stage of the new epidemic, the number of infections imported from other countries can have a huge impact, because even single imported, non particularly annoying subspecies can quickly get out of control. “
This shows that imposing strict travel restrictions at an early stage can play a decisive role in delaying and prolonging the next epidemic, which helps to reduce the burden on the health care system and maximize the use of the facts that arise as we better understand which path to take as the virus evolves.
“I look at these findings from a hopeful perspective. That is, since the number of cases imported by a country in a week becomes so important at an early stage, it means that smart policy-making is actually effective,” the researchers concluded.