Ahead of the COVID-19 'Winter Resurgence'... Simultaneous Emergence of New Variants

Dominant Variant BA.5 Detection Rate Drops from 93.0% to 87.6% in 3 Weeks
BF.7 and BQ.1.1 Sweeping US and Europe Also Rapidly Increasing Domestically

On the morning of the 25th, when the temperature in Seoul dropped to 5 degrees, office workers near Yeouido Station in Seoul put on coats as they headed to work. Photo by Jinhyung Kang aymsdream@

[Asia Economy Reporter Jo In-kyung] As the COVID-19 pandemic shows signs of resurgence, the proportion of various new Omicron variants spreading overseas being detected domestically continues to rise. The 7th major wave of COVID-19, expected to begin next month, is anticipated to be influenced by the transmission patterns of these variants as a new variable.

According to the 'Domestic Omicron Variant Virus Sublineage Detection Rate' analyzed by the Korea Disease Control and Prevention Agency (KDCA) on the 29th, the detection rate of Omicron BA.5 in the third week of this month (16?22) was 87.6%, a 0.8 percentage point decrease from the previous week (88.4%). Compared to three weeks ago, the fourth week of September (93.0%), it dropped by 5.4 percentage points.

In particular, for domestic infections, the BA.5 detection rate fell by 1.6 percentage points from 96.2% in the second week of October to 94.6% in the third week, whereas for imported cases, it decreased by 3.8 percentage points from 61.4% to 57.6%, showing a larger decline. This is interpreted as an increase in new variants other than BA.5 among COVID-19 viruses entering from overseas.

On the other hand, the proportion of BF.7 rose by 0.9 percentage points from the previous week to 2.7%. BF.7 is a sublineage of BA.5 and has recently been spreading in Europe, including Germany, France, and Belgium. It is known to have one additional mutation in the spike protein compared to BA.5, resulting in stronger transmissibility and immune evasion tendencies.

BQ.1, first identified domestically on the 8th of last month, and BQ.1.1, first detected on the 13th, had detection rates of only 0.5% and 0.4% respectively until the second week of this month, but increased to 1.2% and 2.5% in the third week. Notably, the detection rate of BQ.1.1 among imported cases surged from 0.8% to 11.4% within a week. These two variants are also rapidly spreading in the United States and Europe.

Additionally, three cases of the recombinant variant virus XBB, first confirmed domestically earlier this month, were newly detected. XBB is a recombinant variant formed by two subvariants and is considered to have significant immune evasion capabilities.

The health authorities emphasize that although no new variant is prominently increasing its share currently, the simultaneous emergence of various variants calls for active participation in additional winter vaccinations, such as bivalent vaccines.

On the 26th, Baek Kyung-ran, commissioner of the KDCA, stated at a briefing, "After the Omicron BA.2 and BA.5 waves, rather than distinct new variants emerging, sublineage variants continue to appear. Immune evasion by COVID-19 subvariants, waning immunity from infection and vaccination over time, and increased indoor activities during winter may worsen the epidemic."

Earlier, Professor Jung Jae-hoon of the Department of Preventive Medicine at Gachon University College of Medicine said, "Currently, many variants are competing with each other, making it difficult to predict which variant will lead the next wave," but added, "Domestically, the BF.7 variant is expected to cause the initial increase in the next resurgence, with BQ.1 and BQ.1.1 leading the main wave."

This content was produced with the assistance of AI translation services.