A health worker shows an empty syringe after inoculating a woman with AstraZeneca's COVID-19 vaccine during the first day of a nationwide three-day vaccination drive at a school in Quezon city, Philippines on Monday, November 29, 2021. There has been no reported infection so far caused by the new variant in the Philippines, a Southeast Asian pandemic hotspot where COVID-19 cases have considerably dropped to below 1,000 each day in recent days, but the emergence of the Omicron variant has set off a new alarm. (Photo by Aaron Favila/AP Photo)

Dancer of the Berlin State Ballet (Staatsballett Berlin) wear face masks as they perform during the dress rehearsal of Don Quixote in a production choreographed by Victor Ullate, amid the coronavirus disease (COVID-19) pandemic at Deutsche Oper opera house in Berlin, Germany, December 1, 2021. (Photo by Fabrizio Bensch/Reuters)

A local farmer Theophilus Mwendwa runs through a swarm of desert locusts to chase them away in the bush near Enziu, Kitui County, some 200km east of the capital Nairobi, Kenya, 24 January 2020. Large swarms of desert locusts have been invading Kenya for weeks, after having infested some 70 thousand hectares of land in Somalia which the United Nations Food and Agriculture Organisation (FAO) has termed the “worst situation in 25 years” in the Horn of Africa. FAO cautioned that it poses an “unprecedented threat” to food security and livelihoods in the region. (Photo by Dai Kurokawa/EPA/EFE)

Visitors wearing face masks walk near the Gwanghwamun, the main gate of the 14th-century Gyeongbok Palace, and one of South Korea's well-known landmarks, in Seoul, South Korea, Saturday, February 22, 2020. South Korea on Saturday reported a six-fold jump in viral infections in four days to 346, most of them linked to a church and a hospital in and around the fourth-largest city where schools were closed and worshipers and others told to avoid mass gatherings. (Photo by Lee Jin-man/AP Photo)

Kazakh girls watch as the Russian Soyuz TMA-15 rocket carrying Canadian astronaut Robert Thirsk, European Space Agency (ESA) astronaut Frank De Winne of Belgium and Russian cosmonaut Roman Romanenko readies for take-off from the Baikonur cosmodrome, in Kazakhstan on May 27, 2009. Three astronauts, from Canada, Belgium and Russia, blasted off for the International Space Station in a landmark mission that will double its crew to six for the first time. (Photo by Dmitry Kostyukov/AFP Photo)

Ride operator Van Mai wears a face mask against the spread of the coronavirus while working at the Playland amusement park at the Pacific National Exhibition, in Vancouver, British Columbia, Friday, July 10, 2020. (Photo by Darryl Dyck/The Canadian Press via AP Photo)

In this Monday, June 29, 2020 a man wearing a face mask to protect against coronavirus, walks past a hair product billboard on the street in Soweto, Johannesburg, South Africa. Africa now has more than a half-million confirmed coronavirus cases as the continent-wide total is now over 508,000 after South Africa recorded another day of more than 10,000 confirmed cases as a new global hot spot. (Photo by Themba Hadebe/AP Photo/File)

Children in a Hong Kong refugee resettlement area watch as former Vice President Richard Nixon shows them his badminton service. Nixon visited Hong Kong, April 4, 1964, during his tour of countries in the Far East. (Photo by AP Photo)