With the first doses of a vaccine expected to arrive in the region later this month, Pennsylvania and Philadelphia on Wednesday reported new highs in coronavirus cases — a regular occurrence in recent weeks thanks to the fall surge — on a day when the United States reported its highest one-day loss of life yet.

New Jersey Gov. Phil Murphy warned he might tighten the state’s current restrictions if cases there spike in the coming days. Echoing leaders at all levels of government, he warned things could get worse before they get better this winter and urged people in his state to bear down on the public health basics: face masks, social distancing, and handwashing.

“Hang in there. Just stay with us. Stay in the fight. This is only, literally, a matter of a handful of months right now,” Murphy said. “When we talk about light at the end of the tunnel, this is real. And so what we need right now is, we need a bridge from today to that better day, which is not that far forward.”

Getting to that better day will be much easier if Americans follow pandemic safety guidelines, the director of the Centers for Disease Control and Prevention warned Wednesday, predicting that the United States could reach 450,000 deaths by February unless people double down on precautions.

“The reality is December and January and February are going to be rough,” said CDC Director Robert Redfield. “I actually believe they’re going to be the most difficult time in the public health history of this nation.”

It was still too early to know whether Thanksgiving will lead to a surge in infections in the region. Record levels of testing done before the holiday may have affected Philadelphia’s Wednesday case count, the health department said. The spikes in the city and state came after a few days of slightly lower numbers; across the country, testing and reporting rhythms were thrown off by the holiday.

Regardless, the infections, hospitalizations, and deaths continued to increase nationwide. In many areas of the country, the fall surge has not yet peaked, Redfield said in a streamed conversation hosted by the U.S. Chamber of Commerce Foundation. He named Pennsylvania as one of the states seeing a surge that’s yet to crest.

Mitigation measures such as mask-wearing and social distancing are “very, very powerful” in suppressing the spread of the virus, he added: “They have an enormous impact. And right now it is so important that we recommit ourselves to this mitigation as we now begin to turn the corner with the vaccine.”

» READ MORE: Schools with coronavirus cases could be forced to close on short notice under new Pa. rules

In an awful new milestone, the United States reported more than 2,600 new deaths on Wednesday — the highest one-day total since the pandemic began, according to Johns Hopkins University. Nearly 37,000 Americans died of COVID-19 in November, the deadliest month since the first peak of the pandemic began to subside in May.

The CDC recommended people avoid shopping in crowded stores, including supermarkets, until infection rates decline, people shop online, use curbside pickup, or patronize outdoor markets.

Pennsylvania reported 8,291 newly confirmed cases and 194 deaths Wednesday, with 4,982 coronavirus patients hospitalized. The day’s reported death toll was the highest since mid-May.

Philadelphia reported 1,665 new cases and five deaths. The case total was the highest ever reported in one day, but the health department said it had not affected the city’s general case trend because below-average numbers were reported in the preceding days.

“We are more interested in trends than individual numbers,” said Department of Public Health spokesperson James Garrow. “Averaging yesterday’s 601 [new cases] with today’s 1,665 gives us 1,133, which isn’t that much different than what we were reporting last week before the holiday.”

New Jersey added 4,530 cases and 56 deaths. Hospitalizations in the state are continuing to increase.

Describing what the public needs to do over the winter holidays as “Grinch times five,” Murphy asked residents to halt all out-of-state travel unless it was for work or other necessary reasons, and again asked New Jerseyans to be patient over the winter.

“Don’t travel, you gotta stay six feet away from Santa, Santa’s gotta wear a face covering. When you have dinner at home, make sure it’s single digits. … All of that stinks,” Murphy said. “But unfortunately, this is the reality we’re in.”

New Jersey is expected to receive its first batch of the Pfizer vaccine, about 130,000 doses, within weeks, Murphy has said. Those will go to health-care and other frontline workers and vulnerable populations. Vaccines from Moderna should arrive a week later, he said.

But wide availability, Murphy said, remains several months away.

“The news is really good, but it’s not a light switch that we can flip tomorrow,” he said.

Murphy said vaccines could be broadly available by April or May, at which time people can also start returning to outdoor activities.

“Probably not normal-normal, but a new normal that we can much more easily live with and get our arms around,” he said.

» Here are Philly’s current COVID-19 guidelines: inquirer.com/phillyguidelines