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)

Medical staff members wearing protective clothing to help stop the spread of a deadly virus which began in the city, arrive with a patient at the Wuhan Red Cross Hospital in Wuhan on January 25, 2020. The Chinese army deployed medical specialists on January 25 to the epicentre of a spiralling viral outbreak that has killed 41 people and spread around the world, as millions spent their normally festive Lunar New Year holiday under lockdown. (Photo by Hector Retamal/AFP Photo)

Monks attend a prayer service for blessing at the Gandan Temple in Lhasa, capital of southwest China's Tibet Autonomous Region, February 5, 2020. Tibetan Buddhist temples held prayer services to support novel coronavirus-infected areas in China. The monks here were also organized to donate money to help fight against the epidemic. (Photo by Chogo/Xinhua News Agency)

Two brothers have built a human catapult to fly into a lake. Johannes Schrieber, 26, and his brother Daniel, 28, from Frankfurt, Germany built the wooden contraption, which can fire people five metres into the sky and 12 metres away. The brothers raised more than £700 through crowdfunding to buy the materials, with every penny well spent as nobody has died yet! (Photo by Caters News)

Chinese models with animal-themed body paintings pose during a campaign for animal protection at Sanya Color Zoo in Sanya city, south China's Hainan province, 10 January 2016. The girls wearing strapless bras and short pants only were colored with animal-themed paintings such as zebra, cheetah, tiger and peacock. They paraded throughout the newly-opened Sanya Color Zoo and met visitors to take pictures, causing envies from netizens living in north China who are suffering chills. (Photo by Imaginechina/Splash News)

Luling, Louisiana, US. New evidence contradicts previous claims of the relative safety of glyphosate, the world’s most widely used herbicide, which is manufactured here. It is often used in conjunction with seeds that have been genetically modified to tolerate its application, meaning that anyone consuming these crops is eating a genetically modified plant, and whatever residue of the pesticide that remains. (Photo by J. Henry Fair/Industrial Scars/Papadakis Publisher)

Fighters Holly “The Lotus” Mei (L) and Teri “Feisty Fists” London train for the upcoming 'Lingerie Fighting Championships 22: Costume Brawl I' at DXG Self Defense on October 25, 2016 in Las Vegas, Nevada. The event is scheduled to feature eight bouts at 4 Bears Casino & Lodge on October 29, 2016 in New Town, North Dakota. (Photo by Ethan Miller/Getty Images)

Denis and Nelya, both 30, from Moscow, Russia invited brown bear Stepan along to their very special ceremony. As well as witnessing the couple exchange vows, the bear also played the role of registrar at one point. Denis said: “We both knew Stepan is a very kind bear but still it is a huge, unpredictable animal so we were a bit scared, but still happy to be able to make our dream come true. It was a fantastic experience to have this photoshoot with Stepan”. (Photo by Olga Barantseva/Caters News)