COVID-19 is back on the rise as average cases and deaths this week are 1.5x higher compared to the previous week, according to the Centers for Disease Control and Prevention.
COVID hospitalizations have continued to trend upwards in recent weeks and overall hospital bed occupancy is at about 80% – a figure not seen since the omicron surge last winter.
Many experts had warned there would be an uptick in respiratory illnesses following the Thanksgiving holiday where many met without masks or social distancing.
"In the past week, we've started to see the unfortunate and expected rise of COVID-19 cases and hospitalizations nationally after the Thanksgiving holiday," said Dr. Rochelle P. Walensky, director of the CDC, during a telebriefing Monday.
"This rise in cases and hospitalizations is especially worrisome as we move into the winter months when more people are assembling indoors with less ventilation and as we approach the holiday season where many are gathering with loved ones across multiple generations," she added.
MORE: US hospitals are at their highest capacity in a year -- and it's not only due to COVIDIn a press conference Friday, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and Dr. Ashish Jha, White House Coronavirus Response Coordinator, urged Americans to get vaccinated and boosted with a bivalent shot.
"Other vaccines…give you immunity that's lasting in decades, and sometimes a lifetime. Unfortunately, it's not the case with COVID. So we've got to keep up with that virus and keep up with the waning immunity," Fauci said. "When we do that, we're going to wind up being safe. That's the reason why you need your updated COVID booster."
MORE: RSV hospitalizations in seniors much higher than any point in prior seasonsAn estimated 42 million people have not received the updated, bivalent booster, up by about 3 million from last week.
The bivalent booster is specifically formulated to protect against the BA.4/BA.5 variants and has been shown to protect well against newer circulating offshoots such as BQ.1 and BQ.1.1 which make up nearly 70% of new cases.
On Thursday, the Food and Drug Administration authorized bivalent boosters for those down to 6 months of age.
Experts continue to point to vaccinations as a key step to protect oneself and regain a sense of normalcy moving forward.
"Will COVID continue to be disruptive? It may not be – we can get on with our lives, we can do the things that matter to us, if we do certain things – and that's keep up on the vaccination, get treated if you have an infection. If we do that, absolutely, we can stay on top of this virus," Jha said.
ABC News' Sasha Pezenik contributed to this report.