Former Vice President Joe Biden, 2020 Democratic presidential candidate, right, watches as his wife Jill Biden, center, blocks a protester from arriving on stage during an primary night rally in the Baldwin Hills neighborhood of Los Angeles, California, U.S., on Tuesday, March 3, 2020. The biggest day of the presidential primary calendar will define the nomination fight for Bernie Sanders and Biden and determine whether Michael Bloomberg and Elizabeth Warren have a rationale for carrying on their campaigns. (Photo by Patrick T. Fallon/Bloomberg via Getty Images)

A worker sprays disinfectant as sanitization operations against Coronavirus are carried out in the museum hosted by the Maschio Angioino medieval castle, in Naples, Italy, Tuesday, March 10, 2020. (Photo by Alessandro Pone/LaPresse via AP Photo)

Sunrise in Ely, Cambridgeshire on April 15, 2020 by the River Great Ouse, England. The warm weather is set to continue until the weekend. (Photo by Veronica Johansson Poultney/Bav Media)

A woman, her hands decorated with traditional henna, prays during Eid al-Fitr prayer at historical Badshahi mosque in Lahore, Pakistan, Sunday, May 24, 2020. (Photo by K.M. Chaudary/AP Photo)

Dozens of people practice martial arts before the regional Government's headquarters in Barcelona, Spain, 27 July 2020, as a protest against the closure of gyms and martial arts centers in the region imposed by the Catalan Government due to a surge in coronavirus cases. (Photo by Enric Fontcuberta/EPA/EFE)

People take part in a traditional mid-summer solstice night celebration (Rasos Festival) at the Open-Air Museum of Lithuania in Rumsiskes, east of Kaunas, Lithuania, on late June 23, 2020. (Photo by Petras Malukas/AFP Photo)

Seven-year-old Mimi Meade winces from the sting as Dr. Richard Mulvaney inoculates her April 26, 1954 in McClean, Va., with the new Salk polio vaccine. Mrs. John Lucas, a registered nurse, holds Mimi's arm steady as she gets one of the first injections of the countrywide test. (Photo by Harvey Georges/AP Photo)

Lava flows from an eruption of a volcano on the Reykjanes Peninsula in Iceland on March 28, 2021. A week on, big crowds of Sunday hikers flocked to the Fagradalsfjall area to see up close Iceland's latest volcano eruption, as the gentle lava flow allowed people to get close to he eruption some 40 km west of Iceland's capital Reykjavik. (Photo by Halldor Kolbeins/AFP Photo)