PHILADELPHIA (CBS) — There are new warnings about the upcoming holidays of Passover and Easter. Public health officials say COVID-19 cases are increasing and holiday gatherings could make things even worse because not enough people have been vaccinated.

Nearly 5,000 new COVID-19 cases were announced on Friday in Pennsylvania. That’s the most in one day since the end of January. Over the past two weeks, there’s been an increase of 53%.

READ MORE: Teens Age 15, 16, Charged In Series Of Violent Carjackings In Delaware

“Case counts from the corona infection and hospitalizations are continuing to rise,” Philadelphia Health Commissioner Dr. Thomas Farley said.

It’s a trend seen around the country and in the Philadelphia region. COVID-19 is making a comeback, even with an increase in vaccinations.

“We haven’t vaccinated enough people yet to prevent this epidemic wave,” Farley said.

The resurgence is blamed on the contagious variants that are increasing, more people traveling and relaxed mitigation, allowing bigger gatherings.

Alison Beam is the acting Pennsylvania health secretary.

READ MORE: Man, Woman Shot To Death In North Philadelphia

Eyewitness News asked Beam if she’s considering new mitigation efforts to try to stop the new spread of the virus.

“We need folks’ buy-in on this,” Beam said. “We need to make sure they understand that it is still abundantly important they remain masked, that they actually do distancing protocols we put forward.”

After a substantial decline, Pennsylvania cases are trending up. Public health officials are especially concerned about the upcoming holidays of Passover and Easter.

“I’d recommend the same thing we recommended over Christmas and New Year’s. Don’t get together with your relatives, people you don’t live with, over the holidays over a meal,” Farley said. “Some people think testing before is going to help but testing really is not … it can’t be done quick enough or frequently enough to prevent spread there, so it’s a really important time for people to be careful.”

Farley says celebrating inside without a mask is risky, especially for people who aren’t vaccinated. Outside gatherings are much safer.

“If we think things are rising too much, there’s always the opportunity for us to reimpose restrictions,” Farley said. “We’d rather not, though. We hope the vaccination will take us the rest of the way.”

MORE NEWS: Nearly Half Of Nursing Home Workers In Pennsylvania Have Declined COVID-19 Vaccine, State Data Shows

It’s not just Pennsylvania. COVID cases are also increasing in New Jersey and Delaware. The tri-state region is vaccinating a growing number of people. Officials hope that will help control this new resurgence.

Stephanie Stahl