PHILADELPHIA (WPVI) -- As the holidays get underway, health officials and experts say COVID-19 testing will be crucial to managing the pandemic, even for those vaccinated.
After a co-worker tested positive for COVID-19, Francisco Ayala of Frankford says he's probably ditching his Thanksgiving plans.
"Right now, knowing that I don't feel well and he came out positive - that's not going to happen. I'm not going to go out and expose others," said Ayala.
Others got tested for travel or peace of mind Wednesday at Philadelphia's mobile walk-up site along Aramingo Avenue. The location changes from day to day.
"I've got an old mom at home," said Christopher George of Fishtown. "I just wanted to make sure if I was going to go home, she would be alright."
City officials say demand for testing has risen in the past few weeks, and now they're conducting about 7,500 tests per day, and about 3% of those are coming back positive.
"A lot of people who want to travel, a lot of people who want to go to some holiday concerts who want to make sure they're negative so they can enjoy themselves," said testing coordinator Makeida Thomas.
Officials add they're concerned about a holiday surge in COVID-19 cases.
"Not just because of Thanksgiving either. We're starting to see cases rise throughout the country. Pennsylvania is starting to see a real rise in cases," said James Garrow, the communications director for the Philadelphia Department of Public Health.
They say testing is critical before and after gatherings and when you have symptoms.
With many pharmacies and doctor's offices testing by appointment, many people have turned to home test kits if they can find them.
"You have to balance what you're using the test for and the convenience," said Dr. Judith O'Donnell, chief of infectious diseases at Penn Presbyterian Medical Center.
She says home tests are not quite as sensitive as PCR tests, but they are more reliable when used on a patient who experiences symptoms.
"The antigen tests are very good if an individual has symptoms, and they are very accurate in that context," said O'Donnell.
She also said it's very important to follow all instructions carefully if you're using a home test.
If you're traveling internationally and need a negative COVID-19 test upon arrival, make sure to check that country's policy, as not all destinations will accept a home test.
Testing sites will be closed Thursday, but the mobile site will be up and running again Friday and Saturday.
Times and locations will be posted HERE.