In this photo taken Thursday, January 16, 2020, a Samburu boy uses a wooden stick to try to swat a swarm of desert locusts filling the air, as he herds his camel near the village of Sissia, in Samburu county, Kenya. The most serious outbreak of desert locusts in 25 years is spreading across East Africa and posing an unprecedented threat to food security in some of the world's most vulnerable countries, authorities say, with unusual climate conditions partly to blame. (Photo by Patrick Ngugi/AP Photo)

British Prime Minister Boris Johnson visits the Pavegen stand, a company that converts footsteps into energy, at the Innovation Zone during the UK-Africa Investment Summit in London, Britain on January 20, 2020. (Photo by Leon Neal/Pool via Reuters)

A Malaysian Royal Guard wears a protective mask while he stands guard outside National Palace, following the outbreak of a new coronavirus in China, in Kuala Lumpur, Malaysia, February 10, 2020. (Photo by Lim Huey Teng/Reuters)

A man wearing a face mask walks his dog as he pulls a trolley after shopping in Beijing on February 13, 2020. The number of deaths and new cases from China's COVID-19 coronavirus outbreak spiked dramatically on February 13 after authorities changed the way they count infections in a move that will likely fuel speculation that the severity of the outbreak has been under-reported. (Photo by AFP Photo/China Stringer Network)

People participate in the Cordao do Boitata carnival celebration in the Centro City neighborhood on February 16, 2020 in Rio de Janeiro, Brazil. (Photo by Bruna Prado/Getty Images)

A celebrant takes part in the ninth Hong Kong Buddha Sunning Festival at the Tai Mo Shan lookout on February 18, 2020 in Hong Kong, China. The global death toll from the coronavirus epidemic rose above 200, with all but five of those and the vast majority of the more-than 75,000 cases occurring on mainland China. (Photo by Billy H.C. Kwok/Getty Images)

Natalia Williams dressed as Corpse Bride Emily and Tony Knight as a Mandalorian, arrive at the Bradford Unleashed Comic-Con, an entertainment and comic book convention in England on March 8, 2020. (Photo by Danny Lawson/PA Images via Getty Images)

A female tourist wears a protective face mask on the street, following an outbreak of the coronavirus disease (COVID-19), in Tokyo, Japan on March 10, 2020. (Photo by Hannibal Hanschke/Reuters)