Runners participating in this year’s Broad Street Run must be fully vaccinated against COVID-19, according to new guidance from the Philadelphia Department of Health.

All registered in-person runners and volunteers need to receive both doses of the Pfizer or Moderna vaccines, or one dose of the Johnson & Johnson vaccine, by Sunday, Sept. 26 — two weeks before the race date of Sunday, Oct. 10. Participants will receive an invitation to upload their vaccination cards through a secure online registration system.

According to the city, 18,818 runners have registered to participate in the race. In past years, that number was nearly 40,000.

“The Blue Cross Broad Street Run is an annual opportunity for Philadelphians to come together to celebrate the health and vitality of our community,” said Philadelphia Parks and Recreation Commissioner Kathryn Ott. “Getting vaccinated against COVID-19 is the single most important thing any of us can do this year to keep runners, their families, and our community safe.”

The city did not say if it would impose a vaccine mandate on other large outdoor events, such as Eagles games at Lincoln Financial Field, which can hold nearly 70,000 fans. While other teams — the Las Vegas Raiders and New Orleans Saints — have vaccine mandates in place, neither of those mandates were dictated by their respective cities.

The Philly 10K, which takes place Sunday, is also requiring runners to show proof of vaccination or a negative COVID-19 test to participate. The race limited registration to 3,000 runners.

The move comes as more and more businesses require employees and customers to show proof of vaccination following the Federal Drug Administration’s full approval of Pfizer’s two-shot COVID-19 vaccine. Philadelphia continues to see an increase in COVID-19 cases and hospitalizations due to the delta variant, but numbers remain well below peaks seen last winter.

In addition, spectators are “strongly discouraged” by the city from attending the race in person, and won’t be permitted at either the start or the finish line. Cheer zones and other activities along the route will be suspended, and masks are required at the start and finish lines.

Registration for the race is closed, but runners can still elect a virtual option where they run the race route prior to Oct. 11 and have their results merged with the final in-person results.

The race will be broadcast live in its entirety from 7:30 to 10:30 a.m. on NBC10 and Telemundo62 and streamed live on the stations’ digital platforms.

Answers to more questions about the rescheduled race can be found at broadstreetrun.com/faqs.

The annual 10-mile race, first run in 1980, begins at Broad Street and Somerville Avenue in Logan and ends at the Navy Yard in South Philadelphia. The race has raised more than $5 million for the American Cancer Society.