In this April 14, 2014 file photo, Hamamatou Harouna, 10, who lost the use of her legs to polio, crawls to the restroom on the grounds of the Catholic Church where she and hundreds of others found refuge after fleeing violence in her village, in Carnot, Central African Republic. Health authorities on Tuesday, August 25, 2020 are expected to declare the African continent free of the wild poliovirus after decades of effort, though cases of vaccine-derived polio are still sparking outbreaks of the paralyzing disease in more than a dozen countries. (Photo by Jerome Delay/AP Photo/File)

A flock of sheep and goats is led by shepherds to pastures at a mountain village on the outskirts of Sana'a, Yemen, 27 July 2023. At least eight million sheep and goats from about 470,000 pastoralist and agro pastoralist households across Yemen will be treated and vaccinated over the two years 2023 and 2024, in an effort to reduce livestock losses, improve production efficiency, and household income generation amid an acute food insecurity, the UN Food and Agriculture Organization (FAO) has reported. (Photo by Yahya Arhab/EPA)

A robot used to assist Covid-19 patients is seen in an elevator on December 5, 2020 in New Delhi, India. The “Mitra” robot can connect patients with their loved ones, and can assist healthcare workers on the frontlines of the pandemic by minimisng the risk of infections caused by close contact. The Yatharth Hospital, which is treating Covid-19 patients in Noida, on the outskirts of New Delhi, is one of a handful of hospitals in India that has started to use robots. (Photo by Anindito Mukherjee/Getty Images)

Passengers wear protective masks while riding a subway train on April 21, 2020 in Shanghai, China. Health authorities of China said the country has passed the peak of the COVID-19 epidemic on March 12. As of today, the Coronavirus (COVID-19) pandemic has spread to many countries across the world, claiming over 171,000 lives and infecting over 2.4 million people. (Photo by Yves Dean/Getty Images)

A member of the public wears a pandemic face mask ahead of the prime minister announcing the government's Covid-19 winter strategy on September 13, 2021 in Manchester, England. Tomorrow, British Prime Minister Boris Johnson will set out his plan to manage Covid-19 through the winter, including what actions would need to be taken if the NHS hospital system were at risk of being overwhelmed. (Photo by Christopher Furlong/Getty Images)

Students wearing masks rest amid the coronavirus disease (COVID-19) pandemic in Seoul, South Korea, August 25, 2020. (Photo by Kim Hong-Ji/Reuters)

Devotees wearing personal protective equipment (PPE), carry a chariot of Pachali Bhairab amid the spread of coronavirus disease (COVID-19), in Kathmandu, Nepal on October 21, 2020. (Photo by Navesh Chitrakar/Reuters)

A civil defence volunteer wearing a Covid-19 coronavirus-themed helmet holds a placard as he takes part in an awareness campaign at a market in New Delhi on November 25, 2020. (Photo by Sajjad Hussain/AFP Photo)