Miracle Yudo “Kraken” virus: the most contagious strain of covid came to Russia

Latin letters for designating new mutations of the coronavirus have run out, so they began to secretly name them in honor of mythical animals. There were already “Centaur”, “Gryphon”, “Pisces”, and now the “Kraken” has entered the arena. On January 12, Rospotrebnadzor announced the discovery in Russia of a new variant of SARS-CoV-2, which is one of the varieties of Omicron. According to epidemiologists, he easily overcomes immunity after infection with any previous strains, as well as after vaccines. The Kraken is recognized by the WHO as a variant of concern. It has already made waves in the US, causing the highest increase in hospital admissions among older patients since the first Omicron. Now he has begun a procession around the world, having already checked himself in 29 countries.

Rospotrebnadzor reports that the newly-minted offspring of Omicron XBB.1.5 (Kraken) was first identified in Russia in the Penza region. In general, his “homeland” is the United States, where he was discovered in early December last year. Today, he made a powerful wave there, causing a rapid increase in hospitalizations. According to the US Centers for Disease Control (CDC), by the end of the year, almost half of all infections in the country accounted for this subvariant, although two weeks earlier its share did not exceed 10%. “The coming wave is higher than all those recent waves that America has experienced in the spring, summer and autumn,” says the famous American genetic scientist Dmitry Prus.

In addition, Israel reported about the arrival of the Kraken a couple of weeks ago – today this option is becoming dominant there. Since the beginning of 2023, XBB.1.5 has already been found in 29 European countries (France, Denmark, the Netherlands, Germany, etc.), Africa, New Zealand, Canada, and now in Russia.

The Omicron XBB.1.5 sub-variant is a hybrid of the BA.2 and XBB variants. More specifically, he is a direct descendant of XBB.1 (“Hippogryph”), who is himself a descendant of XBB (“Gryphon”). If we continue the theme of Greek mythology, then the kraken is a huge sea monster resembling a giant octopus. Like other mutants, it penetrates cells even better, being able to spread rapidly in the population, and even better evades immunity after illness or vaccination. More precisely, he does not react at all to protective antibodies. “XBB.1.5 differs from the “Singapore” (today widespread in the Russian Federation) XBB.1 by a single, but critical mutation. Moreover, this mutation, F486P, has recently been popular: several subvariants of the coronavirus acquired it at once, and it benefited everyone. The F486P mutation combines evasion of protective antibodies with high penetration into human cells. Rospotrebnadzor reported the discovery of the “Kraken” in the Penza region, but perhaps this is not an imported case, but an example of convergent evolution, when both in America and in Russia XBB.1 naturally acquired the same additional mutation. It does not affect the antigenic properties of the virus so much, but it enhances the binding of the virus to cells and thus can increase infectivity. In practice, “Kraken” is the most contagious of the currently known strains, – Dmitry Prus told “MK”. — New genomic data from Russia show that strains of the XBB family dominated in a number of regions (for example, in Perm and Samara) more than a month ago. Before, I repeat, this situation existed only in Singapore, but the high level of vaccination and a strong healthcare system allowed this city-state to get away with it.”

Some scientists note that in terms of course, consequences and, in general, the degree of danger to humans, the Kraken differs little from previous mutations of the coronavirus infection. And yet, it has a rapid level of contagiousness, therefore it mows down everyone, including those who have literally just been ill with other varieties of the “corona”. Even if you have already been ill with the coronavirus, and more than once, and besides, you are vaccinated, you are not protected from the Kraken. Since the Kraken has masterfully learned to evade the immune system, the body does not recognize it and lets it into the cells. “XBB.1.5 is significantly more infectious due to its better ability to bind to cells. Most of the mutations that allow it to evade immunity are dangerous to cell strength, so it is to be expected that additional mutations will accumulate in XBB.1.5. But before it mutates further, it will cause a substantial surge thanks to its explosive growth. At first, there were allegations that XBB.1.5 was a purely American, even regionally New York phenomenon, and the rapid growth of the Kraken allegedly did not threaten the rest of the world. But no: wherever the new strain has already reached, it behaves equally aggressively, ”says Dmitry Prus.

… The only good news is that the risks of dangerous consequences and deaths in patients with Kraken are much lower than in the original lines of SARS-CoV-2. And yet, its spread during the seasonal surge of acute respiratory viral infections is fraught with the fact that it can be infected simultaneously with the flu, while the likelihood of a severe course and serious complications, as well as exacerbation of chronic diseases, is significantly increased.

According to the experience of other countries, the incidence on the Kraken doubles every 9 days, which means that the incubation period is approximately 7–9 days. As with other variants of coronavirus, all this time a person, without any symptoms, infects others. Symptoms in this subvariant differ little from the symptoms of other seasonal acute respiratory viral infections (temperature above 38 ° C, runny nose, sore throat, muscles and joints, cough, weakness, headache). But aching joints and acute throbbing pain in the muscles with Kraken are more common. At risk are the elderly, chronically ill, children, pregnant women.

Experts expect an increase in the incidence and hospitalizations in Russia by the end of January. “The wave heights of new variants of Omicron are difficult to quantify now, since only a few are officially tested. In terms of hospital workload and virus levels in wastewater, it is currently assumed that the Kraken wave will be the second strongest during the period of Omicron’s dominance. But still, it is significantly weaker than the most starting wave of Omicron a year ago, especially in terms of the most severe morbidity and mortality. This may affect different countries in different ways due to differences in their immune history and health preparedness. Oddly enough, the specifics of the Russian Federation can benefit her. The fact is that in Russia there is an unusually high level of the ancestral strain XBB.1, and this may mean that group immunity in the Russian Federation is more prepared for the Kraken.

At the same time, according to the geneticist, in addition to the risk in the elderly, immunocompromised or for historical reasons with imperfect immunity, Kraken also raises concerns about accelerating the next round of evolution: to form it, it was necessary to change the RNA code twice, and this takes time. The fact is that from virus mutations that occur under the pressure of immunity, the working capacity of the virus usually worsens, and so it gradually becomes softer, and its waves are lower. But exceptions to the rule are possible. Each time the functional properties of a virus are suddenly improved, this means that many new mutations are now available to the virus. Even if such new mutations slightly degrade the quality of the virus, this slide in quality now starts from a new, higher basis and, by and large, does not harm the virus. From an evolutionary point of view, it is predicted that XBB.1.5 functions so effectively that it can acquire several more mutations without losing its infectious potential (after all, as a rule, new mutations help the virus overcome the group immunity left by previous waves, but cost the virus “not free”, weakening the virus). So we will keep an eye not only on the Kraken, but also on the emerging Krakens,” says Dmitry Prus.