Wintour, who is the magazine's editor-in-chief and host of the Met Gala, dropped the news about one of fashion's biggest nights into the bottom of a post she wrote endorsing Joe Biden for the Democratic presidential nomination in which she excoriates President Donald Trump's handling of the crisis.
"Like everyone else, I have been experiencing this COVID-19 crisis as a series of hurtling developments, where one never knows quite what each new day will bring," she wrote on the site.
Wintour, 70, continued: "Through it all one fact, however, remains stubbornly unchanged: President Trump. I, like so many of us, have been appalled by how he has responded to the pandemic—the optimistic and fact-free assurances that all will be fine, the chaotic implementation of travel bans and claims about a 'foreign virus,' the narcissistic ease with which he has passed blame to others, his dishonesty with the American people, and worst of all, his shocking lack of empathy and compassion for those who are suffering and fearful.
"Meanwhile, his administration has been unforgivably slow to provide testing, and to mobilize treatment to all who will need it. These weeks have been a reminder—as if we needed a reminder—that America must choose a new president," she added.
Wintour went on to explain why she backs Vice President Joe Biden.
"I have been impressed with the wider field of Democratic candidates this primary season, but after Biden’s decisive victories on Super Tuesday, I, like so many Americans, made up my mind to rally behind the Vice President," she stated. "He is unmistakably a man of character and has so many qualities that we are in desperately short supply of in Washington right now: decency, honor, compassion, trustworthiness, and best of all experience.
"I know that we will get through COVID-19, but on the other side more challenges await—not the least of which is grappling with our ongoing climate crisis," Wintour continued. "We must choose a president who is ready to govern, who understands how to get results out of Congress, and who can set this country on a path to sustainability. And what a relief it will be to have a president who puts the well-being of others before his own, who doesn’t constantly think of himself first.
She concluded: "For all these reasons, I look forward to casting my ballot in November for Joe Biden—together with whatever running mate he chooses (and he has wisely committed to choosing a woman). I am confident she will be qualified and equipped with the experience that Biden knows—as well as anyone—is required for the job. Election day cannot come soon enough."
As for the gala, it will not be held on its usual date, the first Monday in May, due to the “unavoidable and responsible decision by the Metropolitan Museum to close its doors,” she said.
The event is one of the starriest events of the year: Attendees last year included Lady Gaga, Jennifer Lopez, Serena Williams, Kim Kardashian and Cardi B.
This year's exhibition, "About Time: Fashion and Duration" traces the history of fashion from 1870 to the present in celebration of the museum's 150th anniversary. Among the celebrity hosts previously announced are Lin Manuel-Miranda, Meryl Streep and Emma Stone.
The gala raises money for The Metropolitan Museum of Art's Costume Exhibit and opens the institute's spring exhibition, which has also been delayed.
The Met itself confirmed in a statement to Fox News on March 24 that the exhibit has been rescheduled to early February 2021.
"The Costume Institute's spring 2020 exhibition, About Time: Fashion and Duration, has been rescheduled to run from late October to early February 2021," a spokesperson for the museum said. "The Museum will remain closed to the public and staff until July 1, based on what we are hearing from the CDC and city, state, and federal leaders."
For most people, the new coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia. The vast majority of people recover.
The Associated Press contributed to this report