A flight crew from China Airlines, wearing protective masks, stand in the international terminal after arriving on a flight from Taipei at Los Angeles International Airport (LAX) on February 28, 2020 in Los Angeles, California. The World Health Organization (WHO) has raised the global coronavirus risk level to “very high”. (Photo by Mario Tama/Getty Images)

A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

A waitress of The Palais de Tokyo restaurant wears a protective face mask as a precaution against the coronavirus in Paris, Saturday, September 5, 2020. New French cases of COVID-19 jumped in 24 hours to nearly 9,000, health officials said Friday. The 8,975 new cases were the highest number of infections since France successfully grappled with the spread of the coronavirus during a strict two-month lockdown. There were some 1,800 cases less a day earlier and more than for European neighbors. (Photo by Francois Mori/AP Photo)

People in quarantine exercise in front of their homes amid Covid-19 full lockdown of the city in Shanghai, China, 27 April 2022. According to the Shanghai Health Commission on 27 April, there were 48 new Covid-19 deaths, 1,606 locally transmitted cases, and 11,956 local asymptomatic infections, in Shanghai city. Despite the death toll rising in Shanghai, the number of daily infections has gradually declined. (Photo by Alex Plavevski/EPA/EFE)

A man rides his motorcycle along an empty street in Cali on April 17, 2021, during a curfew imposed by the government to help curb infections of the novel coronavirus, COVID-19, as weekend partial lockdown takes effect in four Colombian cities. In recent weeks, the Colombian government has imposed, and then tightened, a series of restrictions to stem a third wave of infections that is bringing its health system to the brink of collapse. (Photo by Luis Robayo/AFP Photo)

A health worker applies a dose of the AstraZeneca vaccine during the first day of a three-day COVID-19 vaccination campaign for people over age 35 in the Complexo da Maré favela of Rio de Janeiro, Brazil, Brazil, Thursday, July 29, 2021. Some recipients will be monitored to study the rate of protection the vaccines provide and the extent to which virus variants are circulating. (Photo by Bruna Prado/AP Photo)

An injured cat receives treatment at a veterinary clinic by volunteer vets after a forest fire that broke out in Manavgat district of Turkeyâs Antalya on July 31, 2021. At least seven people have died in the wildfires raging in Turkey’s Mediterranean towns, the Turkish health ministry confirmed on 01 August 2021. (Photo by Mustafa Ciftci/Anadolu Agency via Getty Images)

A couple pours water on their dogs during a hot day, in Rome, Thursday, August 12, 2021. In Italy, 15 cities received warnings from the health ministry about high temperatures and humidity with peaks predicted for Friday. The cities included Rome, Florence and Palermo, but also Bolzano, which is usually a refreshing hot-weather escape in the Alps. (Photo by Andrew Medichini/AP Photo)