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)

A patient solves a rubik's cube at a temporary hospital converted from “Wuhan Livingroom” in central China's Hubei Province on February 10, 2020. In face of the outbreak of the novel coronavirus pneumonia epidemic, Wuhan authorities have transformed public venues such as exhibition centers and gymnasiums into temporary hospitals. The hospitals have a large capacity of treating patients with mild symptoms and play an important role in isolating the source of infection and cutting off the routes of infection during epidemic prevention. The first batch of patients was hospitalized on Feb. 5. (Photo by Chine Nouvelle/SIPA Press/Rex Features/Shutterstock)

Dogs wearing masks are seen at a main shopping area, in downtown Shanghai, China, as the country is hit by an outbreak of a new coronavirus, February 16, 2020. (Photo by Aly Song/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 teenager reacts as she receives a shot of the Sinovac vaccine for COVID-19 during a vaccination campaign at a school in Denpasar, Bali, Indonesia on Monday, July 5, 2021. (Photo by Firdia Lisnawati/AP Photo)

A woman reacts as she receives a dose of the COVISHIELD vaccine against the coronavirus disease (COVID-19), manufactured by Serum Institute of India, at a vaccination centre in Ahmedabad, India, December 27, 2021. (Photo by Amit Dave/Reuters)

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 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)