A mother holds her daughter who is injected with a dose of the Soberana-02 COVID-19 vaccine, in Havana, Cuba, Thursday, September 16, 2021. Cuba began inoculating children as young as 2-years-old with locally developed vaccines on Thursday. (Photo by Ramon Espinosa/AP Photo)

Performers entertain passengers at London Heathrow Airport's T3 on Monday, November 8, 2021, as the US reopens its borders to UK visitors in a significant boost to the travel sector. Thousands of travellers are jetting off on transatlantic flights for long-awaited reunions with family and friends. (Photo by Steve Parsons/PA Images via Getty Images)

Participants celebrate the awakening of the Hoppeditz, a fictional character whose return to life marks the start of the carnival season in Düsseldorf, western Germany on November 11, 2021. The 11.11. is celebrated this year again under Corona conditions in presence. However, in the carnival strongholds of Cologne and Düsseldorf, this only applies to the vaccinated and the recovered. (Photo by Federico Gambarini/dpa/Alamy Live News)

Turkey's Yamaha rider Toprak Razgatlioglu celebrates winning the world championship during the World Superbike Championship at the Mandalika International Circuit in Kuta Mandalika, in central Lombok on November 21, 2021. (Photo by Bay Ismoyo/AFP Photo)

Racegoers during Ladies Day at the Grand National Festival at Aintree Racecourse on April 13, 2018 in Liverpool, England. (Photo by Mercury Press)

German troops in Stalingrad, USSR. September 10, 1942. (Photo by TASS)

Two horses appear to burst into laughter before a sweet embrace. The horses both turn their head to look at the camera and flash their teeth, treating the lucky photographer to a rare shot. Moments later the pair show their affectionate side by coming together and “hugging”. Photographer Nir Amos, 34, said he was “amazed” to capture the horses “laughing” in a field near Skógar, in the south east of Iceland on July 31, 2018. (Photo by Nir Amos/Solent News & Photo Agency)

Reveller in costume with a broom jumps during a Zombie Walk event in central Kiev, Ukraine on October 27, 2018, ahead of Halloween celebrations on October 31. (Photo by Anatolii Stepanov/AFP Photo)