Singapore COVID-19 Resurgence Caused by 'XBB' Variant Infection Also Confirmed in Japan

Omicron New Variant with Significant Immune Evasion
Low Severity Rate Likely Means Limited Global Impact

Tokyo Shibuya Street, Japan. Photo by AP Yonhap News

[Asia Economy Reporter Yoon Seul-gi] The first case of infection with 'XBB,' a new subvariant of the COVID-19 Omicron variant, has been confirmed in Tokyo, Japan.

According to Japan's public broadcaster NHK on the 28th, Tokyo announced at a COVID-19 monitoring meeting the previous day that six cases of infection with the XBB variant, which is a combination of multiple virus types, were detected.

As of the 17th, seven cases of the XBB variant were detected during quarantine, but this is the first confirmed case of infection within Tokyo.

Mitsuo Garai, head of Tokyo iCDC, which investigates the variant occurrence situation in Tokyo, stated regarding the XBB variant, "Although it is locally increasing in places like Singapore, there is no sign that it is becoming dominant worldwide, so it is necessary to continue monitoring domestic and international trends."

Recently, the spread of the XBB variant has been increasing in Asia. The XBB variant is a recombinant virus of two subvariants and is known to have stronger transmissibility than existing variants, showing considerable immune evasion. In Singapore, where the detection rate of the XBB variant reaches 80%, the number of new daily confirmed cases surged from about 3,000 in late September to 8,500 on October 18.

The World Health Organization (WHO) explained about the XBB variant, "It shows considerable immune evasion," and "There is concern that it is necessary to ensure that currently used vaccines remain effective in preventing severe illness or death."

However, the severity rate is analyzed to be low. The Institute for Health Metrics and Evaluation (IHME) at the University of Washington in the United States predicted that people with a history of infection with the BA.5 variant may have immunity against XBB, so the global impact may not be significant.

Meanwhile, it has been found that there are about 300 subvariants of Omicron, including the XBB variant, spreading worldwide. As COVID-19 prolongs, Omicron subvariants appear to be continuously evolving.

The WHO International Health Emergency Committee stated on the 20th (local time), "Although the virus is expected to continue evolving, the genetic and antigenic characteristics of future variants cannot yet be reliably predicted," adding, "This is due to significant current gaps in international surveillance that hinder early identification and assessment of such changes."

They continued, "Since the start of the COVID-19 pandemic, the global situation has clearly improved, but the virus continues to change, and many risks and uncertainties remain," and "This pandemic has surprised us before and will continue to do so."