Arcturus, new highly contagious Covid variant is spreading rapidly
The XBB.1.16 coronavirus variant, also known as Arcturus, after it caused the number of infections in India to increase by 281% in 14 days, has attracted the attention of experts around the world. The number of deaths also increased by 17% in the same period. Vipin Vashishta, a pediatrician, researcher and member of the WHO vaccine group, warned on Twitter: “If Arcturus could break the immunity of the population of Indians who have successfully resisted the onslaught of previous variants, then the whole world seriously needs to worry!” Not yet clear whether there really is a reason for the “mood of alarm”. While some experts, such as the German virologist Martin Strmer, recommend watching the development “very closely” due to Arcturus, others are already advising caution. “There is no reason to panic,” quotes the former head of the Indian Coronavirus Task Force, Randeep Guleria, in the Times of India. There have been almost no serious cases so far, and appropriate behavior would reduce the risk of infection. However, XBB.1.16 has now reached 22 countries. These include the United States, Singapore, Australia, Japan, Great Britain, Italy, Denmark and Austria. The variant of the Omikron family has also been detected in Germany. In many cases, however, travelers from India could be identified as the source of the infection.
Arcturus a recombination of omicron subvariants. According to the “Deutsche Apothekerzeitung” (DAZ), it probably descends from BA.2.10 and BA.2.75 and has already evolved many times. XBB.1 and XBB.1.5 were already rampant around the world. The latter has been the dominant variant in the United States since December. According to the World Health Organization (WHO), the XBB family is growing worldwide and has replaced the previously dominant BA.5 and BA.2 variants almost everywhere. XBB.1.16 has several mutations in the spike protein that are already known from XBB.1.5. However, there are more new ones coming to Arcturus. One of these is the S486P mutation. It means that the virus can bind even better to the ACE2 receptor and ensures that the virus can penetrate the cells of the human body even faster. This would make XBB.1.16 even more infectious than other variants. Until now, the XBB1.5 variant was considered the fastest spreading variant. According to the DAZ, the new XBB.1.16 variant is expected to have a 140% growth advantage over it. Arcturus has additional mechanisms that block the body’s immune response: according to Friedemann Weber, head of the Institute of Virology at the University of Giessen, XBB.1.16 “has a number of other changes in the genome that not only affect the spike protein, but also the so-called ORF9b gene, which is involved in the suppression of the interferon response”. Interferons are messenger substances produced by infected cells to warn other cells of the infection and to initiate countermeasures. Sars-CoV-2 has a whole range of these so-called interferon antagonists and ORF9b has not been one of the strongest representatives so far. The variant, notes Giovanni DAgata, president of the Rights Desk, could thus weaken the immune system of vaccinated and recovered people, which explains the sharp increase in infections in India.