"We have 52 countries represented, which is from all around the city, so vaccination clinics and education awareness about where to get vaccines during the week is crucial to making this happen," said Unity Cup Director Bill Salvatore.
Some events are issuing their own requirements - the Made in America Festival and Philly 10k run are some of the city's first to require a vaccine or negative COVID-19 test.
"I think it's great," said Marty Whitaker of Wynnewood. "I think we need that, more things like that, just to make sure when we come into contact with one another that everybody knows that everybody is taken care of."
RELATED: In-person participants must have COVID-19 vaccination for 2021 Broad Street Run
Organizers of the Broad Street Run, which takes place on October 10, announced all participants must be fully vaccinated by September 26.
They say proof of a negative COVID test is not an option. Spectators are strongly discouraged from attending the race in person.
In addition, cheer zones along the race route will be suspended.
Juan Guch of Prospect Park has participated in the Broad Street Run eight to nine times. He said he'd rather have the city cancel it than have it without spectators.
"It just helps you run faster," said Guch. "You see people cheering, you get excited, you get a rush of all the people there, and then you enjoy the race more than just struggling on your own running 10 miles."
Medical professionals say the safest way to attend a large event is to be vaccinated and continue following COVID-19 protocols.
"Be mindful of where you are going. If it's a closed indoor event and there are large amounts of people there, you have to be smart about it and make sure you're still wearing your mask," said family physician Dr. Delana Wardlaw.