Omicron has been making headlines as cases of the new COVID-19 variant continue to be detected in the United States. While the strain is concerning, health officials are heeding that delta continues to fuel widespread transmission and is a problem now.
That's the current case in Pennsylvania, where the number of daily confirmed COVID-19 infections crossed 10,000 Friday for the first time since the state's winter wave.
In the past week, the number of COVID-19 cases, case rates, hospitalizations and patients on ventilators have all gone up, according to state data. Amid its latest surge, Pennsylvania has one of the highest COVID-19 hospitalization rates in the U.S.
"We continue to see a tremendous amount of COVID-19 patients," Dr. Eugene Curley, the medical director of infectious disease for WellSpan Health, which has six acute care hospitals in south-central Pennsylvania, told ABC News.
One month ago, there were about 250 COVID-19 patients total being treated across the six hospitals; on Friday, that number was 310, Curley said. The peak, during last year's winter surge, was around 430, he said.
The University of Pittsburgh Medical Center, which operates over 35 hospitals throughout Pennsylvania, has seen its second-highest number of COVID-19 patients since the pandemic began, hospital officials said. As of Friday morning, there were 779 patients with active COVID-19 infections admitted across all UPMC facilities; the peak, in December 2020, was 1,250, UPMC Chief Medical Officer Dr. Donald Yealy told ABC News.
"Across our system, we're at about two-thirds to three-quarters of what that peak is," he said. "So it is very, very brisk."
The state's current surge has been building since late summer, Yealy said. It reached a peak in late September before "there was the beginning of a pullback in activity," Yealy said.
"That pullback no longer exists and we are back on essentially an upward trajectory," he continued.
It's hard to predict if Thanksgiving gatherings will have an impact on hospitalizations; holidays are a "wild card," Curley said. But many people in the state have no protection against COVID-19, Yealy noted, which will help fuel transmission.
Statewide, around 41% of residents have still not gotten fully vaccinated, according to federal data. Within some counties, that percentage is in the 60s, state data shows.
For the 30 days ending Nov. 2, nearly 75% of people hospitalized due to COVID-19 were unvaccinated, according to state data.
Across WellSpan's six acute-care hospitals, over 90% of COVID-19 patients in the ICU and on ventilators since early September have been unvaccinated, the health system said this week.
"Those numbers just reinforce what we already know -- is these vaccinations are safe and effective," Curley said.
Pennsylvania Gov. Tom Wolf has urged people to get vaccinated if they haven't already.
"In Pennsylvania and around the country, the vaccine is still our strategy, so get your shot," the governor said last week on KDKA-AM radio, according to The Associated Press.
A renewed push for vaccination and boosters has come amid the spread of omicron, which has concerned scientists due to its large number of mutations. The variant has been detected in at least 11 states -- including Pennsylvania, where the state's first case was identified Friday in a man from northwest Philadelphia, health officials said.
For Curley, if concerns around the omicron variant encourage people to get vaccinated, that's a good thing. But he warned that delta "is here now."
"People need to get vaccinated for that reason," he said. "If you're out there and you're eligible to be vaccinated, get vaccinated now because of delta."
Rochelle Walensky, director of the Centers for Disease Control and Prevention, echoed that sentiment on Friday in an interview on CNN.
"We now have about 86,000 cases of COVID right now in the United States being diagnosed daily and 99.9% of them, the vast majority of them, continue to be delta," she said. "And we know what we need to do against delta. And that is get vaccinated. Get boosted if you're eligible and continue all of those prevention measures, including masking."
It is too soon to tell if omicron will overtake delta as the predominant variant in the U.S., she said. Though either way, the actions will likely remain the same, experts say.
"The truth of the matter is, both delta, which is the predominant variant now, and omicron are easily transmitted. And so the concerns are really not changed all that much, and the actions that we all need to take remain exactly the same," Yealy said. "Get vaccinated, wear a mask indoors and in crowds, keep a little distance and if you get sick, don't go out with others and get tested as quickly as possible."
ABC News' Cheyenne Haslett contributed to this report.