Covid-19: what we know about the XBB variant that is spreading in Singapore – BFMTV

Singapore is facing a resurgence of the Covid-19 outbreak, driven by the XBB subvariant. A mutation of the coronavirus which would not cause more serious illness than the other variants. The sub-variant of Omicron, called XBB, has been emerging for a few weeks in certain Asian countries, such as Singapore or Bangladesh. XBB is a sub -variant of Omicron which was detected at the end of 2021. Although it is more contagious than Delta, it is also less virulent than the latter. More specifically, XBB is a recombinant, that is, a variant that has been created by combining the genetic material of two different variants. In this case, strains BJ.1 and BA.2.75, themselves sub-variants of Omicron. Where does it emerge? In recent weeks, XBB has led to a resurgence of the Covid-19 epidemic in Singapore. The Ministry of Health said that the country had more than 6,800 cases of Covid-19 on Wednesday on a rolling 7-day average, compared to less than 3,000 at the end of September. This new sub-variant has also been detected in Bangladesh, Denmark , in the United Kingdom, Australia, Belgium and Austria.Despite this resurgence of the epidemic, “the number of serious cases has remained relatively serious,” said the Singaporean Ministry of Health on Tuesday. “This is most likely due to the resistance accumulated by vaccination and previous waves of infection,” he added. Do vaccines remain effective? “Faced with the resurgence of the epidemic, Singapore has decided to administer from Friday the bivalent vaccine designed by Moderna and Spikevax, which specifically targets the Omicron vaccine, to certain categories of people, such as those aged 50 and over. mRNA vaccines containing variants, which include Omicron BA.1 or BA.4/5 subvariants to the original virus, have been cleared for use as booster doses. These vaccines, however, can only offer a “tiny additional benefit”, however, specified on Wednesday the group of experts who advise the World Health Organization on vaccination. “The data currently available are not sufficient to support the issuance of a recommendation in favor of booster doses containing bivalent variants” compared to vaccine doses based on the original virus, he said in a statement. According to a study by Chinese scientists, pre- published on October 4 and which has not yet been peer-reviewed, the recombinant XBB would be particularly resistant to antibodies. According to this study, this would mean that “booster vaccines designed on the basis of BA.5” – which is also a subvariant of Omicron – “may not provide broad-spectrum protection against infection”. variant Omicron accounted for 99.9% of virus samples collected and sequenced as part of the global science initiative GISAID over the past 30 days. Among them, the BA.5 group of Omicron subvariants remained overall dominant at 81%, followed by the BA.4 mutation at 8% and the BA.2 subvariant at 3%.