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)

A motor taxi driver gets his hands washed at an Ebola screening station on the road between Butembo and Goma on July 16, 2019 in Goma. The first patient to be diagnosed with Ebola in the eastern DR Congo city of Goma has died, the governor of North Kivu province said on July 16, 2019. The case – the first in a major urban hub in the region's nearly year-old epidemic of the disease – has sparked deep concern in neighbouring Rwanda and at the UN. (Photo by John Wessels/AFP Photo)

Senegalese wrestlers cover themselves in sand as they prepare to start their training program in Petit Mbao on March 29, 2021. As Covid-19 restrictions have been lifted, wrestlers now start prepare themselves for the start of wrestling tournaments. Senegalese wrestling, which has its roots in the ceremonies celebrating the end of harvests in Serer and Diola ethnic groups and remains surrounded by a thick cloud of mystical practice, is still extremely popular in this West African country. (Photo by John Wessels/AFP Photo)

Soldiers from the Nigerian Armed Forces take position and secure the streets in Lagos Island, Lagos, on February 27, 2023, after hoodlums had harassed market owners. Nigeria slowly counted more results on Monday after a tight election for the presidency of Africa's most populous nation as delays and accusations of manipulation fuelled tensions Nearly 90 million were eligible to vote on Saturday for a successor to President Muhammadu Buhari, with many hoping for a new leader to tackle insecurity, economic malaise and widening poverty. (Photo by John Wessels/AFP Photo)

Against the scorching sun, a hungry jackal chases a flock of birds looking for a quick morning snack. Taken in South Africa's Kgalagadi Transfrontier National Park, these images capture the moment a lone hunter tries, and then succeeds, in his pursuit. (Photo by John Mullineux/Solent News)

A rider rears up on his horse while surrounded by a cheering crowd during the traditional Fiesta of San Joan (Saint John) in downtown Ciutadella, on the Spanish Balearic Island of Menorca, June 23, 2014. The riders of the horses are representatives of ancient Ciutadella society – nobility, clergy, craftsmen and farmers. (Photo by Enrique Calvo/Reuters)

Meatball, a bulldog, poses in a tuxedo at the Tompkins Square Halloween Dog Parade on October 20, 2012 in New York City. Hundreds of dog owners festooned their pets for the annual event, the largest of its kind in the United States. (Photo by John Moore)

A cloud of black smoke billows out the exhaust pipe of John Robertson's diesel dragster as he runs down the track during the 2015 NHRA Kansas Nationals, Friday, May 22, 2015, at Heartland Park in Topeka, Kan. (Photo by Chris Neal/The Topeka Capital-Journal via AP Photo)