The Fast-Spreading New COVID-19 Subvariant XBB Is Part of a ‘New Class’ of Omicron

In the ever-changing landscape of COVID-19 variants, a new player has emerged and is causing concern among experts. XBB, also known as Gryphon, is a subvariant of the Omicron strain that is gaining momentum and has the potential to surpass its predecessors. Known for its rapid spread and ability to evade immunity, XBB is capturing the attention of doctors and researchers who are closely monitoring its trajectory.

XBB belongs to the “new class” of Omicron variants that are currently surging, alongside BQ.1.1, BQ.1, BQ.1.3, BA.2.3.20, and others, according to Thomas Russo, an infectious disease expert at the University at Buffalo. This hybrid strain combines elements of the BA.2 form of Omicron and has demonstrated efficient transmission, particularly in Singapore.

Initially detected in India in August 2022, XBB has since been identified in over 17 countries, including Australia, Bangladesh, Denmark, India, Japan, and the United States. Researchers in China have conducted a pre-print study highlighting XBB’s unique ability to evade antibody protection compared to other newly emerged variants. The study suggests that XBB is the most antibody-evasive strain tested, surpassing BA.5 and even approaching the level of SARS-CoV-1, the coronavirus strain responsible for causing SARS.

This raises concerns about the effectiveness of vaccines and previous COVID-19 infections in providing protection against XBB. The pre-print study suggests that antibody drugs like Evusheld and bebtelovimab may also exhibit limited efficacy against XBB. As variants continue to evolve to evade immune protection, experts like Dr. Russo emphasize the importance of bivalent boosters in preventing severe disease, although they may be imperfect at preventing infection.

Despite the potential challenges posed by XBB, there is no need for panic. Dr. Amesh Adalja of the Johns Hopkins Center for Health Security reassures that vaccine protection is not an all-or-none scenario. While immune-evasive variants may reduce the effectiveness of vaccines against infection, they still offer significant protection against severe disease, which remains paramount.

The symptoms associated with XBB appear to align with the general symptoms of COVID-19, including fever, cough, fatigue, and loss of taste or smell, among others, as reported by the Centers for Disease Control and Prevention (CDC).

Like other Omicron strains, XBB is believed to be highly contagious. Singapore’s Ministry of Health states that XBB now accounts for 54% of COVID-19 cases in the country, up from 22% the previous week. However, there is currently no evidence suggesting that XBB causes more severe illness than other variants.

The future trajectory of XBB remains uncertain. While it has been detected in the United States, BA.5 and BA.4.6 continue to dominate as the prevailing variants, according to CDC data. Additionally, other variants are also emerging simultaneously, making it unclear whether XBB or another related variant, such as BQ.1.1, will become dominant in the U.S.

Experts like Dr. Schaffner emphasize the importance of closely monitoring the situation in the coming weeks. As the COVID-19 pandemic rapidly evolves, staying informed through reputable sources such as the CDC, WHO, and local health departments is crucial. Consulting with healthcare professionals for personalized medical advice is always recommended.

Please note that the information provided in this article is accurate as of press time, but the COVID-19 landscape is continuously evolving, and new developments may have emerged since publication.