Nevertheless, said Dr. David Pride, an infectious disease specialist at UC San Diego, “just looking at [the current situation] epidemiologically, we know something is way different this time around.”

With so many unvaccinated people out there, he added, “it was just a matter of time before we’d see a mutated version of the virus that is just better at infecting vaccinated people.”

It’s practically an evolutionary imperative, said Jasmine Plummer, a research scientist at Cedars-Sinai Medical Center in Los Angeles who was part of the team that discovered the Epsilon variant of the virus last winter.

“Variants arise because of viruses trying to survive,” Plummer said. “All viruses evolve to evade their host. So we knew an Omicron was coming.”