(NewsNation Now) — As omicron races ahead of other variants and is officially the dominant version of the virus in the United States, the former U.S. Surgeon General warned that the variant could be the straw that breaks the camel’s back as the country still struggles to recover from the delta variant surge.

Omicron accounted for 73% of new infections last week, federal health officials said Monday. Since the end of June, the delta variant had been the main version causing U.S. infections. As recently as the end of November, more than 99.5% of coronavirus cases were delta, according to data from the Centers for Disease Control and Prevention.

Former U.S. Surgeon General Jerome Adams warned while that while omicron was sweeping across the nation, this was not the last we have seen of the delta variant.

“People really need to understand is we’re still going to see this delta surge filling up hospitals for another two to three weeks, we’re gonna see it run the course. Then any cases of omicron end up in the hospital on top of that really could be the straw that breaks the camel’s back,” Adams said on “Morning in America.” “And then people won’t be able to get care for heart attacks, or strokes, or car wrecks.”

This comes just days after the nation’s top infectious disease expert, Dr. Anthony Fauci, said the omicron variant was “just raging around the world.” 

“We really are in a bad situation right now in terms of the spread of this virus and people need to understand that as we go into the holiday season,” Adams told NewsNation’s Adrienne Bankert.

Much about the omicron variant remains unknown, including whether it causes more or less severe illness. Early studies suggest the vaccinated will need a booster shot for the best chance at preventing omicron infection but even without the extra dose, vaccination still should offer strong protection against severe illness and death.

“We have not seen definitively that this virus is less severe than the delta variant. What many of us actually believe is that this new omicron variant is encountering many more people who have immunity, either because they’ve been vaccinated, or because they’ve been previously infected,” Adams said. “It appears less severe because it’s encountering a different environment than what previous viruses did. Why that’s important is because if you’re not vaccinated right now, you still could end up in the hospital due to omicron. And to your point, the real key here is our hospital capacity literally cannot handle anything more on top of this current delta surge.”

Adams warned that hospitals across the country were being pushed to their limit and that receiving the coronavirus vaccine would lessen the chances of hospitalization.

More than 60% of the population have received two coronavirus vaccine doses or are fully vaccinated, according to data to compiled by the Centers for Disease Control and Prevention. Adams said he believes that since not everyone will get vaccinated, the coronavirus vaccine will turn into a yearly one, like the flu vaccine.

“I think after everyone gets their third dose of vaccine, we’re going to settle into a yearly rhythm the way we do with flu,” Adams said. And just like with flu, some people get vaccinated, those who don’t may end up in the hospital, we need to get them tested quickly.”

Biden is set to deliver remarks on the variant Tuesday afternoon. In a preview of Biden’s speech, White House press secretary Jen Psaki said at Monday’s press briefing that Biden doesn’t plan to impose any lockdowns and will instead be encouraging people to get inoculated — and, if they’re eligible, to get their booster shot.

About one in six Americans have received their booster shot, according to data complied by the CDC.