A girl reacts as she receives polio vaccine drops during a house-to-house vaccination campaign in Yemen's capital Sanaa, November 10, 2015. (Photo by Khaled Abdullah/Reuters)

Taras Mychalewych, 75, poses for a portrait with his vaccination card after receiving his coronavirus disease (COVID-19) vaccine at a rural vaccination site in Columbus, New Mexico, U.S., April 16, 2021. (Photo by Paul Ratje/Reuters)

A resident receives a dose of Pfizer BioNTech COVID-19 vaccine at a rural village on December 01, 2021 in Aringay, La Union province, Philippines. The Philippines is rushing to vaccinate its population as it mulls making COVID-19 vaccination mandatory and amid the looming threat of the Omicron variant of the coronavirus. The country, which has just approved booster shots for its adult population, launched a three-day national vaccination holiday on November 29 to December 1 with the goal of vaccinating at least nine million additional people. (Photo by Ezra Acayan/Getty Images)

Surfers take to the waves at Bondi Beach on October 16, 2021 in Sydney, Australia. COVID-19 restrictions eased across NSW on Monday 11 October for fully vaccinated residents after the state passed its 70 per cent double vaccination target. (Photo by Brook Mitchell/Getty Images)

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)

Health workers watch as the vaccine against the Coronavirus arrives at a nursing home in l'Hospitalet de Llobregat in Barcelona, Spain, on Sunday, December 27, 2020. The first shipments of coronavirus vaccines developed by BioNTech and Pfizer have arrived across the European Union, authorities started to vaccinate the most vulnerable people in a coordinated effort on Sunday. (Photo by Emilio Morenatti/AP Photo)

Leanna Arcila, 7, is licked by Watson, a therapy dog with the Pawtucket police department, as she receives her COVID-19 vaccination from Dr. Eugenio Fernandez at Nathanael Greene Elementary School in Pawtucket, R.I., Tuesday, December 7, 2021. Even as the U.S. reaches a COVID-19 milestone of roughly 200 million fully-vaccinated people, infections and hospitalizations are spiking, including in highly-vaccinated pockets of the country like New England. (Photo by David Goldman/AP Photo)

A girl receives Covid-19 vaccine as Nepal Government begins vaccinating children aged 5-12 at a school in Kathmandu on June 23, 2022. (Photo by Aryan Dhimal/ZUMA Press Wire/Rex Features/Shutterstock)