Every few months for the first two years of the pandemic the public learned the name of a new coronavirus variant that had emerged and was more adept at infecting us or causing severe disease. Ten variants with Greek names—Alpha through Mu—killed millions. Then in November 2021, Omicron, a vastly different version of the virus emerged. For the past 10 months the World Health Organization hasn’t named any new variants, which begs the question: Has the virus stopped evolving?
At least 300 Americans have died from COVID-19 every day for the past three months and roughly 50,000 new COVID-19 infections were reported in the U.S. every day in September—all caused by new sublineages of Omicron: BA.2, BA.2.12.1, BA.4., and BA.5. Infection rates among U.S. nursing home residents have risen nine-fold since the end of April, and by August death rates almost quadrupled in this group, according to the data compiled by the AARP Public Policy Institute and the Scripps Gerontology Center at Miami University in Ohio. In the United Kingdom, often a harbinger of COVID-19 trends in the U.S., symptomatic infections have steadily increased since August 27—the day they hit lowest level this year—according to the ZOE COVID-19 study, an App-based project in which patients enter their symptoms on their phone. While WHO has not anointed any of these recent Omicron derivatives with a Greek letter of their own, experts fear these variants could undermine the new boosters and treatments, leading to a new wave of infections and deaths.
The coronavirus is continuously evolving and gaining novel mutations; to date there have been more than 200 newer Omicron sublineages and their derivatives. “SARS-CoV-2 evolution is not over,” says Olivier Schwartz, head of the Virus & Immunity Unit at Institut Pasteur, Paris.