"Signs of Winter Resurgence?" ... Spread of New COVID-19 Variants Worldwide

BA.5 Subvariants BF.7 and BQ.1.1 Confirmed in Europe and the US
BA.5 Prevalence Decreases While Subvariant Cases Rise Domestically

[Image source=Reuters Yonhap News]

[Asia Economy Reporter Kim Young-won] This winter, as influenza spreads in the Northern Hemisphere alongside another expected resurgence of COVID-19, the share of new COVID-19 variants is increasing in various countries overseas.

According to the Central Disease Control Headquarters on the 13th, a further mutation of the Omicron subvariant BA.5, named BQ.1.1, has been identified in some European countries including the United Kingdom.

The UK Health Security Agency (UKHSA) explained in a report that variants starting with BQ, along with BA.2.75.2 and BF.7, are currently the most concerning in terms of growth and neutralization data. BQ.1.1 has not yet been detected domestically.

As various new variants emerge, confirmed cases are also increasing. According to the World Health Organization (WHO), the global weekly number of confirmed cases from the 26th of last month to the 2nd of this month decreased by 6% compared to the previous week, whereas in Europe, cases increased by 8%. In particular, Germany reported 402,014 weekly confirmed cases, a 42% increase compared to the previous week.

Im Sook-young, head of the Central Disease Control Headquarters’ situation management team, explained, "In countries such as Germany, France, and Belgium, where the proportion of BA.5 and BA.4 subvariants is increasing, recent case numbers are rising."

BF.7 is spreading in the United States, but confirmed cases are still on a downward trend. According to the U.S. Centers for Disease Control and Prevention (CDC), from the 2nd to the 8th of this month, the share of the BF.7 variant in the U.S. rose to 4.6%, up 1.3 percentage points from 3.3% the previous week. The U.S. is seeing a decrease in BA.5 proportions while other variants are increasing. BA.5 remains dominant at 79.2%, followed by BA.4.6 (13.6%) and BF.7, all increasing weekly.

Domestically, the detection rate of the dominant BA.5 is decreasing, while the proportion of other subvariants is rising. As of the 8th, the detection rate of the BA.2.75 variant, known as "Kentauros," increased from 2.4% the previous week to 2.8%. The detection rate of BF.7, a BA.5 subvariant, rose about fourfold from 0.3% to 1.3%. The BJ.1 subvariant of BA.2, which was prevalent in the first half of this year, was detected 15 more times, increasing its detection rate from 0.5% to 1.0%. Meanwhile, the detection rate of BA.5, which had risen to 97.4% in the second week of last month, dropped to 90.6%.

Domestic experts advise that although the COVID-19 epidemic is showing a downward trend, more thorough surveillance is necessary given the emergence of various detailed subvariants. According to forecasts from seven domestic research teams announced by the Korea Disease Control and Prevention Agency, the scale of the COVID-19 resurgence is expected to increase to about 2,000 to 21,000 cases per day two weeks from now. The research teams pointed out, "The possibility of an increase in confirmed cases over the next month is low, but considering the recent emergence of various detailed subvariants and the rebound of the epidemic overseas, careful observation and evaluation are necessary."

Overseas experts noted that the increase in confirmed cases in some countries is not entirely due to variants but could be a factor causing future resurgences. Tom Bensellis, a professor of biology at the Catholic University of Leuven in Belgium, said in an interview with foreign media, "The recent increase in cases is not only due to new variants but also due to waning immunity," adding, "However, variants will cause a resurgence." Regarding the scale of the epidemic, he predicted, "The number of infections this fall and winter will be similar to the BA.5 resurgence."