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)

These kaleidoscopic images showcase the sheer beauty of the mammoth firework displays held across Japan every summer. The Japanese word for fireworks, hanabi, means fire flower, and each year, local governments in Japan throw around 7,000 festivals, or hanabi taikai. Here: Tsuchiura National Fireworks Competition, Tsuchiura City, Ibaraki Prefecture. (Photo by Makoto Igari/Caters News Agency)

Here are the bravest of the brave in 2016. Weve gathered some of the finest images showing daredevils taking their lives into their own hands and going to the very brink this year. Whether they are perched hundreds of feet up on a high wire, courageously clinging to a rockface or taking on a volcano, these adventurers take the breath away. Here: Morgane Choquet and Samuel Cobb relax in a vertical campsite on the slopes of El Capitan, Yosemite National Park. (Photo by Alexandre Eggermont/Caters News)

These hilarious photos will leave people wedding themselves with laughter. The images – which include photobombs, wardrobe malfunctions and unexpected animal behaviour – have been released by the International Society of Professional Wedding Photographs (ISPWP). Each year the society holds quarterly competitions, celebrating a variety of the best image from couples special days. Other categories in the ISPWPs completions include the likes Getting Ready, First Dance, Family Love, and a selection of portrait possibilities. Here: Couples wedding photo photobombed by deer. (Photo by Hendra Lesmana/Caters News Agency/ISPWP)

India's Border Security Force (BSF) soldiers ride their camels during a rehearsal for the “Beating the Retreat” ceremony in New Delhi, India, January 27, 2016. The ceremony symbolises retreat after a day on the battlefield, and marks the official end of the Indian Republic Day celebrations. It is held every year on January 29. (Photo by Anindito Mukherjee/Reuters)

Belarussian villagers perform during a celebration of the “Tsary” rite in the village of Semezhevo, Belarus January 13, 2016. This unique rite originated from the 18th century, and now takes place only in this village marking the New Year, according to the Julian calendar, on January 13. (Photo by Vasily Fedosenko/Reuters)

Toby, an 11-year-old German shepherd-husky mix, can hold almost anything on his head that his owner, Pat Langner, can think up, including balls, Christmas trees, and even the ingredients for a peanut butter and jelly sandwich. He also shows remarkable self-restraint by not immediately gobbling down the food that his owner gives him to balance. Here: Toby balances halloween decorations on his head. (Photo by Pat Langer/Caters News Agency)