Well, here’s one small consolation in light of the recent COVID-19 outbreak in China that has killed at least 60,000 people (and likely far more): A new study suggests that the vast majority of infections were caused by existing variants—and not some super-Kraken strain that the rest of the world has yet to experience.
Scientists mainly from the Beijing Center for Disease Prevention and Control genetically sequenced the viral RNA of thousands of confirmed COVID-19 cases from 2022, including 413 samples from Nov. 14 to Dec. 20 alone. Their study detailing the results of the sequencing was published Feb. 8 in The Lancet.
“Our analysis suggests two known Omicron subvariants—rather than any new variants—have chiefly been responsible for the current surge in Beijing, and likely China as a whole,” George Gao, director-general of Chinese Center for Disease Control and Prevention and a co-author of the new paper, said in a press release. “However, with ongoing large-scale circulation of COVID-19 in China, it is important we continue to monitor the situation closely so that any new variants that might emerge are found as early as possible.”
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The researchers found that, within their sample, two Omicron subvariants—BA.5.2 and BF.7—made up 90 percent of local cases in Beijing. These subvariants have been circulating in America for months, according to the U.S. Centers for Disease Control and Prevention’s variant tracker. These days, however, U.S. cases are largely made up of Omicron variants B.Q.1.1 and XBB.1.5, which are masters at evading immunity.
“This is exactly what you'd like to do to monitor populations in real time to see how the variant composition is changing,” Michael Pfrender, the director of the Genomics & Bioinformatics Core Facility at University of Notre Dame told The Daily Beast. Pfrender, who was not involved in the research, called the team’s ability to collect and analyze the data for the study and publish it just over a month later “remarkable,” but added that it is too early to be sure that no new variants emerged during China’s outbreak.
For one thing, the researchers only analyzed COVID-19 samples from Beijing, which may not be representative of the country as a whole. Additionally, the number of samples that the researchers sequenced pales in comparison to the number of infections during the recent wave, and so a new variant could have fallen through the cracks.
“Given their estimate of the number of cases and how many samples they actually sequenced, they're only looking at about 1 percent of the infections,” Pfrender said. “A brand new variant that comes into a population will come in at very low frequency until it gains some momentum and starts to spread, so the sample that they have really wouldn't tell you about new emerging variants that are still at low frequency.”
It might seem surprising that BA.5.2 and BF.7 were the variants that dominated this recent outbreak when there is evidence suggesting a more recent variant like XBB.1.5 spreads faster among people. In the study, the authors wrote that they found several cases of this variant, BQ.1, and BQ.1.1 in travelers returning from another country. These strains may not have become widespread in Beijing yet because of “current effective quarantine measures for the imported cases, and the potential protective effect that is offered by the outbreak in progress,” wrote the researchers.
Going forward, it will be helpful to see whether results from larger sequencing studies agree with this study’s findings, Pfrender said.
So it seems the old proverb applies to predicting and tracking emerging COVID-19 variants: No news is good news.
