Dominic Lipinski | Pa Pictures Getty Images Japan has reported the first case of omicron XE – a new strain of Covid-19 first detected in the UK – as the UK cases of the subvariable increase. The XE variant was found on a woman in her 30s who arrived at Narita International Airport from the United States on March 26. The woman, whose nationality was not immediately disclosed, was asymptomatic, the Japanese Ministry of Health said on Monday. It comes as the number of new executives has almost doubled in Britain, according to the latest statistics from the UK Health Insurance Agency. As of 5 April, 1,125 XE cases had been detected in the UK, up from 637 on 25 March. The first confirmed case has a sample date of January 19 of this year, indicating that it could be circulating in the population for several months. Since then, XE has been detected in Thailand, India and Israel. There are suspicions that the latest Israeli cases may have developed independently. The US has not yet reported XE cases.
What is omicron XE?
XE is what is known as “recombinant”, a type of variant that can occur when a person becomes infected with two or more variants at the same time, resulting in the mixing of their genetic material into the patient’s body. In the case of XE, it contains a mixture of the previously highly infectious strain omicron BA.1, which appeared in late 2021, and the newer “stealth” variant BA.2, currently the dominant variant of the United Kingdom. Such recombinations are not uncommon, as they have occurred several times during the coronavirus pandemic. However, health experts say it is too early to draw conclusions about the severity or ability of the new subtype to avoid vaccines. “We continue to see cases of recombinant XE variant in the UK, which currently accounts for a very small proportion of cases,” said Meera Chand, Director of Clinical and Emerging Infections at UKHSA. On Sunday, the United Kingdom reported 41,469 new Covid cases, with a seven-day average of 59,578 cases. As a result, XE probably accounts for only a small percentage of all Covid cases at present.
How much should we worry?
Preliminary estimates suggest that the XE may be more contagious than previous strains, having so far shown a slightly higher growth rate than its predecessor. UKHSA data show that XE has a growth rate of 9.8% above that of BA.2, while the World Health Organization has so far set this percentage at 10%. However, experts say they expect it to decrease in severity even when it spreads more easily. XE has so far not been declared a variant of concern. “XE seems to be moving in the same direction as BA.2, with increased transmissibility in BA.1 but it is less severe,” Jennifer Horney, a professor of epidemiology at the University of Delaware, told CNBC. “He’s the devil we know, let’s say. [It is] “essentially a rearrangement of the same deck,” added Mark Cameron, an associate professor in medical school at Case Western Reserve University.
CNBC Health & Science
Read CNBC’s latest global coverage of the Covid pandemic: XE contains spikes and structural proteins from the same virus family, namely the micron, which means that it should, in theory at least, behave like the micron in the past. Existing vaccines and immunity should therefore provide some level of protection against infection. “Recombinants containing the spike and structural proteins from a single virus (such as XE or XF) are quite likely to act similarly to [their] “parent virus,” wrote Tom Peacock, a virologist in the Infectious Diseases Department at Imperial College London, in a thread tweets in mid-March. XF refers to another recombination previously detected in the UK in February. However, other recombinations containing spikes and structural proteins from different virus families continue to occur. This includes the XD sub-variant, recently discovered in Germany, the Netherlands and Denmark, which contains delta structural proteins and micron spike proteins, which Peacock described as “a little more worrying”. Therefore, all new appearances must be closely monitored, especially in their early stages, to ensure that they do not develop into something more serious. “The virus is still capable of evolving, recombining and developing a new branch of its family tree,” Cameron said. “The key is that for each of these variants and sub-variants, the risk of hospitalization and death appears to be, on average, lower where vaccination rates are higher, indicating that vaccination, including a third dose, should be effective in reducing the risk of serious illness, “added Stephanie Silvera, a professor of public health at Montclair State University.
