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)

Participants wearing costumes and masks take part in the first day of the traditional carnival parade in Mohacs, Hungary, 23 February 2017. The carnival parade of so-called busos, dressed in costumes with frightening wooden masks and using various noisy wooden rattlers, is traditionally held on the seventh weekend before Easter to drive away winter. (Photo by Sandor Ujvari/EPA)

“The King”, Johnathon Haddock poses for a portrait with the Garland before the procession during “Castleton Garland Day” on May 29, 2019 in Castleton, England. The first records of Garland day date back to the 1700's and though it's true origins are not fully understood it is believed to be an ancient fertility rite with Celtic connections. (Photo by Dan Kitwood/Getty Images)

Female metro passengers hold flowers presented to them by metro workers, prior to International Women's Day in Kiev, Ukraine, 02 March 2016. The hustle and bustle of the morning commute is broken up by an unexpected surprise. The first passengers to step on the train receive – a warm welcome and a pot of flowers. One woman says, “It's very nice. All the running around and then you're given a flower, it's not often. It's very nice. I'm going to take care of this flower”. International Women's Day first emerged from the activities of labour movements at the turn of the twentieth century, in North America and across Europe, it is celebrated on March 08 in many countries around the world. (Photo by Sergey Dolzhenko/EPA)

A performer dressed as a Hello Kitty poses inside a Hello Kitty-themed Taroko Express train in Taipei, Taiwan March 21, 2016. Lucky fans of Hello Kitty were among the first to ride a train themed after the iconic fictional character on its inaugural run in Taiwan on Monday. The Hello Kitty-themed Taroko Express train, the first in Taiwan, set off from the Shulin train station and will travel to Taitung on the east coast route. The Taiwan Railway Administration, which will introduce Hello Kitty merchandise, said it plans to adds more themed trains to its fleet. (Photo by Tyrone Siu/Reuters)

In this Thursday, May 16, 2013 file photo, Finland's Krista Siegfrids, second right, kisses a dancer as she performs her song “Marry Me” during the second semifinal of the Eurovision Song Contest at the Malmo Arena in Malmo, Sweden. That was the first girl-on-girl kiss in the history of the annual competition. Previously, organizers had sought to prevent similar embraces citing the competition's status as a family event. (Photo by Alastair Grant/AP Photo)

Rowers enter in Canaregio river during the 42nd Venice Vogalonga on May 15, 2016 in Venice, Italy. 42 years ago a group of Venetians, both amateur and professional rowers, came up with an idea of non-competitive race in which any kind of rowing boat can take part. The first Vogalonga began with the message to protest against the growing use of powerboats in Venice and the swell damage they do to the historic city. (Photo by Awakening/Getty Images)

Performers re-enact the 1947 massacre of Taiwanese intellectuals by mainland China's Nationalists troops during the inauguration ceremony of Taiwan's President Tsai Ing-wen in Taipei, Taiwan, Friday, May 20, 2016. Taiwan inaugurated Tsai as its first female president on Friday, returning the pro-independence Democratic Progressive Party to power amid new concerns over increasingly fractious relations with Beijing and a flagging economy. (Photo by Chiang Ying-ying/AP Photo)