A nurse at St. Joseph's Hospital wears a unique mask as the hospital celebrates the release of a COVID-19 patient after 45 days in their care during the outbreak of the coronavirus disease (COVID-19) in Orange, California, U.S., May 5, 2020. (Photo by Mike Blake/Reuters)

A boy walks by a model of a dinosaur wearing a face mask, during a partial lockdown to prevent the spread of the coronavirus, at the Museum of Natural History in Brussels, Tuesday, May 19, 2020. Museums are hesitantly starting to reopen as the coronavirus lockdown measures are relaxed, yet experts say that one in eight in the world could potentially face permanent closure because of the pandemic. (Photo by Virginia Mayo/AP Photo)

A health worker dresses in a protective suit before starting to perform the coronavirus testing in an effort to stop the spread of the coronavirus disease (COVID-19) in the Kibera slum of Nairobi, Kenya, May 26, 2020. (Photo by Baz Ratner/Reuters)

Students with torches protest against the alleged encroachment of Nepal border by India in far west of Nepal, during the 49th day of a lockdown imposed by the government amid concerns about the spread of the coronavirus disease (COVID-19), in Kathmandu, Nepal on May 11, 2020. (Photo by Navesh Chitrakar/Reuters)

A man designs a face mask with the photograph of a customer printed on it, amid the spread of the coronavirus disease (COVID-19), at a photo studio in Gandhinagar, India, May 27, 2020. (Photo by Amit Dave/Reuters)

Visitors and a dog stand on the new “Skywalk” viewing platform on the Sonnenstein mountain in the Eichsfeld region near Bad Lauterberg im Harz, central Germany, on May 22, 2017. (Photo by Martin Schutt/AFP Photo/DPA)

A masked Burundian protester faces soldiers in front of a burning barricade during an anti-government demonstration against President Pierre Nkurunziza's bid for a third term in the capital Bujumbura, Burundi, 25 May 2015. Street protests continued on 25 May as the United Nations Secretary-General Ban Ki-moon condemned the killing of the leader of the oppsition party Union for Peace and Development (UPD) Zedi Feruzi who opposed Nkurunziza's bid. (Photo by Dai Kurokawa/EPA)

Russians play accordions as they walk near the building of the Federal Security Service (FSB, Soviet KGB successor) in Lubyanskaya Square to mark May Day in Moscow, Russia, Sunday, May 1, 2016. As in Soviet times, about one hundred thousand of cheerful workers paraded across Red Square despite a chilly rain, but instead of red flags with the Communist hammer and sickle, they waved the blue flags of the dominant Kremlin party and the Russian tricolor. (Photo by Alexander Zemlianichenko/AP Photo)