Recently, the World Health Organization (WHO) announced preliminary research findings regarding a new variant of the SARS-CoV-2 virus.
Earlier, the WHO confirmed that the BA.2 sublineage of the Omicron variant is currently the primary cause of COVID-19 cases globally, particularly in Europe and Asia, raising concerns about the potential outbreak of a new wave in the United States.
Image provided by the U.S. Food and Drug Administration regarding the SARS-CoV-2 virus causing the COVID-19 respiratory illness.
BA.2 currently accounts for 86% of all sequenced COVID-19 cases. BA.2 has been shown to spread 30% faster than the original BA.1 strain of the Omicron variant. Just as BA.2 became the dominant variant, a new variant emerged, which is believed to potentially spread even faster than BA.2.
Recently, scientists have been monitoring three new variants: XD, XF, and XE. Among these, the XD and XF variants are hybrid forms of the Delta variant and BA.1, often referred to as Deltacron. These two variants have been mentioned for several months but have not yet caused significant changes in the global pandemic situation.
Meanwhile, the XE variant is a recombinant form combining the BA.1 and BA.2 variants of Omicron. Recombinant variants occur when an individual is simultaneously infected with two or three variants of the virus, allowing the genetic material of the variants to mix within the infected person’s body. This is not unusual, as it has occurred several times during the COVID-19 pandemic.
According to preliminary research results compiled by the WHO, XE was first identified in the UK on January 19, with over 600 gene sequencing samples confirmed as the XE variant. Early estimates suggest that XE has a community transmission growth rate approximately 10% higher than BA.2.
However, further time and research are needed to confirm this. Currently, many WHO member countries have reduced the number of tests for SARS-CoV-2, resulting in less data, slower reporting, and non-representative samples, making it more challenging to collect and compile data, significantly hindering the WHO’s virus tracing efforts. Additionally, there is still too little regional data to draw more accurate conclusions about this variant.
Last week, the UK Health Security Agency (UKHSA) submitted a brief report to the WHO, which included some information regarding the XE variant. According to UKHSA, there is evidence that XE is spreading within communities in England, although it currently accounts for only 1% of the total samples analyzed. Initial data on the growth rate of cases due to XE infection does not show any significant difference from BA.2.
However, based on the latest data as of March 16, the growth rate of cases due to this variant may be 9.8% higher than BA.2. Professor Susan Hopkins, Chief Medical Advisor at UKHSA, stated that XE is a unique recombinant variant, with a growth rate of infection unlike previous variants and that more time is needed to specifically identify the characteristics of this variant. UKHSA is continuing to monitor the situation.
Currently, XE still represents a very small portion of the total global COVID-19 cases, but if the growth rate of cases due to this variant is indeed more than 10% higher than BA.2, then XE’s transmission potential could be 43% higher than Omicron, the variant that has dominated globally in recent months. Nevertheless, concerns that BA.2, the currently dominant variant, could lead to new waves of infection have not yet materialized, even as many countries have lifted restrictions. Scientists remain hopeful that the trends in the disease caused by XE will also follow a similar pattern.
