Yes, omicron has overtaken delta. No, it’s not March 2020.

Although details about the omicron variant are still sketchy, a picture is starting to emerge – and it’s not all bad news.

As the omicron variant sweeps across the world and pushes out the delta variant that preceded it, scientists are rushing to understand how it might change the coronavirus pandemic, now entering its third year. So far, it’s clear that omicron is highly contagious – roughly twice as contagious as delta and four times more than the original virus.

Experts worry that even if it’s less virulent, which isn’t yet clear, it could still cause enough hospitalizations to overwhelm health care systems here and abroad. But this is not 2020. Back then, only a handful of people on earth had been exposed to the SARS-CoV-2 virus that causes COVID-19. Everyone’s immune system was unprepared.

Today, the vast majority of Americans have either contracted COVID-19 or been vaccinated once, twice or three times against it. That should – though there are still no hard numbers to confirm it – provide people protection against severe disease and death.

“I think we should reassure people that if they’ve been vaccinated with two doses or naturally infected, they’re likely protected against serious illness,” said Dr. Paul Offit, a pediatric infectious disease expert and director of the Vaccine Education Center at Children’s Hospital of Philadelphia.

What’s not clear is how people who have never been vaccinated or contracted COVID-19, or whose protection has waned significantly over time, will fare if they catch omicron.