The New York City Marathon, the world’s largest marathon and one of the city’s biggest annual spectacles, has been canceled this year as concerns about the spread of the coronavirus continue to dash hopes of holding large-scale events, organizers announced Wednesday.

The race, one of the most prestigious and lucrative events of its kind, would have celebrated its 50th anniversary in November. It is one of the highlights of fall in New York and on the endurance sports calendar, attracting more than 50,000 runners, 10,000 volunteers and roughly one million fans, who line nearly every accessible yard of the 26.2-mile course through the five boroughs.

City officials and New York Road Runners, which owns and organizes the event, decided holding the race would be too risky.

Public health experts have said mass events, especially those that bring people together from across the globe, will remain a danger until a treatment or a vaccine for Covid-19, the disease caused by the virus, is widely available.

White House officials have issued warnings about another wave of infections this fall. And while infection rates in the New York metropolitan area are now among the lowest in the country, the virus is spreading at concerning rates in areas that have not heeded the advice of public health officials to continue to practice social distancing, avoid public gatherings and wear masks.

Cases were rising in 26 states on Tuesday night.