German Health Minister Jens Spahn removes his face mask before addressing a press conference on the situation of flu vaccines and the coronavirus disease (COVID-19) pandemic, in Berlin, Germany October 6, 2021. Odd Andersen/Pool via REUTERS 

Soccer Football - Copa Libertadores - Quarterfinal - First leg - Fluminense v Barcelona - Estadio Maracana, Rio de Janeiro, Brazil- August 12, 2021 Fluminense's Marcos Felipe wearing a protective face mask during the warm up Pool via REUTERS/Sergio Moraes 

Soccer Football - Brasileiro Championship - Fluminense v Bahia - Maracana stadium, Rio de Janeiro, Brazil - October 11, 2020 General view of a statue wearing a face mask outside the stadium before the match REUTERS/Sergio Moraes 

Soccer Football - Brasileiro Championship - Fluminense v Palmeiras - Maracana Stadium, Rio de Janeiro, Brazil - August 12, 2020 A staff member wearing a protective face mask before the match, following the resumption of play behind closed doors after the outbreak of the coronavirus disease (COVID-19) REUTERS/Pilar Olivares 

Soccer Football - Brasileiro Championship - Gremio v Fluminense - Arena do Gremio, Porto Alegre, Brazil - August 9, 2020 A staff member wearing a protective face mask during halftime, following the resumption of play behind closed doors after the outbreak of the coronavirus disease (COVID-19) REUTERS/Diego Vara 

Soccer Football - Brasileiro Championship - Gremio v Fluminense - Arena do Gremio, Porto Alegre, Brazil - August 9, 2020 Gremio coach Renato Gaucho wearing a protective face mask before the match, following the resumption of play behind closed doors after the outbreak of the coronavirus disease (COVID-19) REUTERS/Diego Vara 

A child and his grandmother wear face masks as they hold their arms after receiving a vaccine as part of the start of the seasonal flu vaccination campaign as a preventive measure due to the outbreak of coronavirus disease (COVID-19), in Santiago, Chile, March 16, 2020. Picture taken March 16, 2020. REUTERS/Ivan Alvarado 

Children wearing face masks attend a mathematics lesson at the Yuri Gagarin school in the town of Divnogorsk near Krasnoyarsk, Siberia, Russia, February 4, 2016. Regional authorities have instructed employees of nursery and educational institutions to wear face masks as a prevention against the spread of swine flu, an epidemic which has swept the Russian regions, causing the death of over 100 people, local media reported. REUTERS/Ilya Naymushin 

Teacher Anastasiya Trifonova and children wear face masks during a mathematics lesson at the Yuri Gagarin school in the town of Divnogorsk near Krasnoyarsk, Siberia, Russia, February 4, 2016. Regional authorities have instructed employees of nursery and educational institutions to wear face masks as a prevention against the spread of swine flu, an epidemic which has swept the Russian regions, causing the death of over 100 people, local media reported. REUTERS/Ilya Naymushin 

Teacher Anastasiya Trifonova and a girl wear face masks during a mathematics lesson at the Yuri Gagarin school in the town of Divnogorsk near Krasnoyarsk, Siberia, Russia, February 4, 2016. Regional authorities have instructed employees of nursery and educational institutions to wear face masks as a prevention against the spread of swine flu, an epidemic which has swept the Russian regions, causing the death of over 100 people, local media reported. REUTERS/Ilya Naymushin 

Teacher Yelena Bogdanova (C) wearing a face mask conducts a literature lesson at the Yuri Gagarin school in the town of Divnogorsk near Krasnoyarsk, Siberia, Russia, February 4, 2016. Regional authorities have instructed employees of nursery and educational institutions to wear face masks as a prevention against the spread of swine flu, an epidemic which has swept the Russian regions, causing the death of over 100 people, local media reported. REUTERS/Ilya Naymushin 

Children wearing face masks attend a mathematics lesson at the Yuri Gagarin school in the town of Divnogorsk near Krasnoyarsk, Siberia, Russia, February 4, 2016. Regional authorities have instructed employees of nursery and educational institutions to wear face masks as a prevention against the spread of swine flu, an epidemic which has swept the Russian regions, causing the death of over 100 people, local media reported. REUTERS/Ilya Naymushin 

A woman wearing a face mask gets out of a train on the subway in Moscow, Russia, January 28, 2016. Over 100 people have died of swine flu in Russia since December according to data from the country's regional health authorities, local media reported. REUTERS/Maxim Zmeyev 

A woman wearing a face mask is seen inside a train on the subway in Moscow, Russia, January 28, 2016. Over 100 people have died of swine flu in Russia since December according to data from the country's regional health authorities, local media reported. REUTERS/Maxim Zmeyev 

A prisoner reacts as he receives a flu shot from a nurse during a health campaign at Lurigancho prison in Lima June 11, 2013. The campaign by the Ministry of Health provides specialized care in pulmonology, dermatology, ophthalmology, gastrology as well as vaccinations to at-risk groups in the prison, according to a media release. Lurigancho prison is one of the most overcrowded, violent, and unruly jails in Latin America with more than 8,500 prisoners. REUTERS/Mariana Bazo (PERU - Tags: CRIME LAW HEALTH SOCIETY TPX IMAGES OF THE DAY) 

A couple wearing face masks walk at the Bund along the Huangpu River in downtown Shanghai April 5, 2013. Chinese authorities were slaughtering birds at a poultry market in the financial hub Shanghai as the death toll from a new strain of bird flu mounted to six on Friday, spreading concern overseas and sparking a sell-off on Hong Kong's share market. All of the 14 reported infections from the H7N9 bird flu strain have been in eastern China and at least four of the dead are in Shanghai, a city of 23 million people and the showpiece of China's vibrant economy. REUTERS/Aly Song (CHINA - Tags: DISASTER HEALTH ANIMALS) 

A man wearing a face mask walks at the Bund along the Huangpu River in downtown Shanghai April 5, 2013. Chinese authorities were slaughtering birds at a poultry market in the financial hub Shanghai as the death toll from a new strain of bird flu mounted to six on Friday, spreading concern overseas and sparking a sell-off on Hong Kong's share market. All of the 14 reported infections from the H7N9 bird flu strain have been in eastern China and at least four of the dead are in Shanghai, a city of 23 million people and the showpiece of China's vibrant economy. REUTERS/Aly Song (CHINA - Tags: DISASTER HEALTH ANIMALS) 

Women wearing face masks walk at the Bund along the Huangpu River in downtown Shanghai April 5, 2013. Chinese authorities were slaughtering birds at a poultry market in the financial hub Shanghai as the death toll from a new strain of bird flu mounted to six on Friday, spreading concern overseas and sparking a sell-off on Hong Kong's share market. All of the 14 reported infections from the H7N9 bird flu strain have been in eastern China and at least four of the dead are in Shanghai, a city of 23 million people and the showpiece of China's vibrant economy. REUTERS/Aly Song (CHINA - Tags: DISASTER HEALTH ANIMALS) 

A woman wears a face mask inside a subway station in Shanghai, April 5, 2013. Chinese authorities were slaughtering birds at a poultry market in the financial hub Shanghai as the death toll from a new strain of bird flu mounted to six on Friday, spreading concern overseas and sparking a sell-off on Hong Kong's share market. State news agency Xinhua said the Huhuai market for live birds in Shanghai had been shut down and birds were being culled after authorities detected the H7N9 virus from samples of pigeons in the market. All of the 14 reported infections from the H7N9 bird flu strain have been in eastern China and at least four of the dead are in Shanghai, a city of 23 million people and the showpiece of China's vibrant economy. REUTERS/Carlos Barria (CHINA - Tags: DISASTER HEALTH) 

A woman wearing a face mask walks along a shopping area in downtown Shanghai, April 5, 2013. Chinese authorities were slaughtering birds at a poultry market in the financial hub Shanghai as the death toll from a new strain of bird flu mounted to six on Friday, spreading concern overseas and sparking a sell-off on Hong Kong's share market. State news agency Xinhua said the Huhuai market for live birds in Shanghai had been shut down and birds were being culled after authorities detected the H7N9 virus from samples of pigeons in the market. All of the 14 reported infections from the H7N9 bird flu strain have been in eastern China and at least four of the dead are in Shanghai, a city of 23 million people and the showpiece of China's vibrant economy. REUTERS/Carlos Barria (CHINA - Tags: DISASTER HEALTH ANIMALS) 

Men wearing face masks are pictured on an escalator at a shopping mall area in downtown Shanghai, April 5, 2013. Chinese authorities were slaughtering birds at a poultry market in the financial hub Shanghai as the death toll from a new strain of bird flu mounted to six on Friday, spreading concern overseas and sparking a sell-off on Hong Kong's share market. State news agency Xinhua said the Huhuai market for live birds in Shanghai had been shut down and birds were being culled after authorities detected the H7N9 virus from samples of pigeons in the market. All of the 14 reported infections from the H7N9 bird flu strain have been in eastern China and at least four of the dead are in Shanghai, a city of 23 million people and the showpiece of China's vibrant economy. REUTERS/Carlos Barria (CHINA - Tags: DISASTER HEALTH ANIMALS) 

A man wears a face mask as he walks in a shopping area in downtown Shanghai April 5, 2013. Chinese authorities were slaughtering birds at a poultry market in the financial hub Shanghai as the death toll from a new strain of bird flu mounted to six on Friday, spreading concern overseas and sparking a sell-off on Hong Kong's share market. All of the 14 reported infections from the H7N9 bird flu strain have been in eastern China and at least four of the dead are in Shanghai, a city of 23 million people and the showpiece of China's vibrant economy. REUTERS/Carlos Barria (CHINA - Tags: DISASTER HEALTH) 

A man wearing a face mask holds a balloon while standing with his daughter in an MTR train in Nam Cheong, Hong Kong January 21, 2011. Hong Kong's Thomas Tsang Ho-fai, controller of the Department of Health's Centre for Health Protection urged people to raise their guard after a bird carcass collected in Yuen Long on Monday tested positive for the H5 strain of bird flu. 149 cases of flu were recorded since the past week, local media reported. REUTERS/Joel Boh (CHINA - Tags: TRANSPORT HEALTH) 

Malaysia's number one badminton player Lee Chong Wei puts on a face mask as he is given a massage after a training session, ahead of the Thomas Cup and Uber Cup, in Kuala Lumpur May 4, 2010. Malaysia's badminton world championship prospects have been salvaged following a scare triggered when a national coach was hospitalised with swine flu. Malaysia is hosting the 26th Thomas Cup and 23rd Uber Cup, which will take place in Kuala Lumpur from May 9-16. REUTERS/Bazuki Muhammad (MALAYSIA - Tags: SPORT BADMINTON HEALTH) 

Malaysia's number one badminton player Lee Chong Wei receives a massage wearing a face mask after a training session in Kuala Lumpur May 4, 2010. Malaysia's badminton world championship prospects have been salvaged following a scare triggered when a national coach was hospitalised with swine flu. REUTERS/Bazuki Muhammad (MALAYSIA - Tags: SPORT BADMINTON HEALTH) 

Two women wear face masks as they queue with other people outside Matei Bals hospital to take shots against the H1N1 flu virus in Bucharest, January 9, 2010. The country, which has recorded 6,061 cases of infection and 82 deaths, began a mass vaccination campaign last year but less than one percent of the 22 million population has been so far immunised due to people's reluctance and poor infrastructure. At least 12,220 deaths from H1N1 flu has been formally confirmed around the globe as of December 27, the World Health Organisation said. REUTERS/Radu Sigheti (ROMANIA - Tags: HEALTH SOCIETY POLITICS IMAGES OF THE DAY) 

A Palestinian hospital worker wears a face mask at al-Shifa hospital in Gaza City December 6, 2009.H1N1 swine flu has finally reached the Gaza Strip, the health ministry said on Sunday, worrying Palestinians who had credited Israel's blockade of the territory with keeping the virus at bay. REUTERS/Mohammed Salem (GAZA POLITICS HEALTH) 

Palestinian doctors wear face masks at the reception of al-Shifa hospital in Gaza City December 6, 2009. H1N1 swine flu has finally reached the Gaza Strip, the health ministry said on Sunday, worrying Palestinians who had credited Israel's blockade of the territory with keeping the virus at bay. REUTERS/Mohammed Salem (GAZA POLITICS HEALTH) 

A Palestinian doctor wears a face mask at the reception of al-Shifa hospital in Gaza City December 6, 2009. H1N1 swine flu has finally reached the Gaza Strip, the health ministry said on Sunday, worrying Palestinians who had credited Israel's blockade of the territory with keeping the virus at bay. REUTERS/Mohammed Salem (GAZA POLITICS HEALTH) 

Palestinian hospital workers wear face masks at Kamal Odwan hospital in the northern Gaza Strip December 6, 2009. H1N1 swine flu has finally reached the Gaza Strip, the health ministry said on Sunday, worrying Palestinians who had credited Israel's blockade of the territory with keeping the virus at bay. REUTERS/Ismail Zaydah (GAZA HEALTH POLITICS) 

A Palestinian hospital worker wears a face mask at Kamal Odwan hospital in the northern Gaza Strip December 6, 2009. H1N1 swine flu has finally reached the Gaza Strip, the health ministry said on Sunday, worrying Palestinians who had credited Israel's blockade of the territory with keeping the virus at bay. REUTERS/Ismail Zaydah (GAZA HEALTH POLITICS IMAGES OF THE DAY) 

A market vendor, wearing a face mask, stands in front of a large pile of sacks containing garlic at an outdoor food market in Beijing November 25, 2009. The price of garlic in China has nearly quadrupled since March, propelled by its very pungence to rank ahead of gold and stocks as the country's best performing asset this year. The trigger for the bull run, according to Morgan Stanley economists, may have been the idea that the potent bulb can help ward of the H1N1 virus, popularly known as swine flu. REUTERS/David Gray (CHINA SOCIETY BUSINESS) 

A market vendor, wearing a face mask, stands in front of a large pile of sacks containing garlic at an outdoor food market in Beijing November 25, 2009. The price of garlic in China has nearly quadrupled since March, propelled by its very pungence to rank ahead of gold and stocks as the country's best performing asset this year. The trigger for the bull run, according to Morgan Stanley economists, may have been the idea that the potent bulb can help ward of the H1N1 virus, popularly known as swine flu. REUTERS/David Gray (CHINA SOCIETY BUSINESS) 

Ukraine's fans, wearing face masks as preventive measures against the H1N1 flu, cheer during the second leg of the 2010 World Cup qualifying soccer match in Donetsk November 18, 2009. REUTERS/Gleb Garanich (UKRAINE SPORT SOCCER HEALTH) 

Russia's fans wearing face masks as preventive measures against the H1N1 flu watch the 2010 World Cup qualifying soccer match against Slovenia in Moscow, November 14, 2009. REUTERS/Sergei Karpukhin (RUSSIA SPORT SOCCER) 

Russian fans wear face masks as a preventive measure against the H1N1 flu react during their 2010 World Cup European qualifying playoff against Slovenia in Moscow November 14, 2009. REUTERS/Mikhail Voskresensky (RUSSIA SPORT SOCCER) 

A Russia fan and a policeman wearing face masks as preventive measures against the H1N1 flu watch Russia's World Cup 2010 playoff qualifying soccer match against Slovenia in Moscow November 14, 2009. REUTERS/Sergei Karpukhin (RUSSIA SPORT SOCCER) 

Russia's fans, and police wearing face masks as preventive measures against the H1N1 flu, watch the 2010 World Cup qualifying soccer match in Moscow, November 14, 2009. REUTERS/Sergei Karpukhin (RUSSIA SPORT SOCCER IMAGES OF THE DAY) 

A man in a protective face mask passes by an installation by British artist Harland Miller titled "I Was Always Good at Finding Things I" featuring a group of people in Tyvek protective suits taking bacteriological samples in central Kiev, November 13, 2009. The installation is staged by Pinchuk Art Centre as a response to the situation developing around the H1N1 flu epidemic announced in Ukraine. REUTERS/ Konstantin Chernichkin (UKRAINE ENTERTAINMENT SOCIETY HEALTH) 

Children wear face masks for protection against the H1N1 flu virus at a school in Bucharest November 10, 2009. Romania's health authorities declared on Tuesday that 1001 people have been infected with the H1N1 virus since the first case in the Balkan country was reported in May. REUTERS/Bogdan Cristel (ROMANIA HEALTH EDUCATION) 

Children wear face masks for protection against the H1N1 flu virus at a school in Bucharest November 10, 2009. Romania's health authorities declared on Tuesday that 1001 people have been infected with the H1N1 virus since the first case in the Balkan country was reported in May. REUTERS/Bogdan Cristel (ROMANIA HEALTH EDUCATION) 

Children wear face masks for protection against the H1N1 flu virus at a school in Bucharest November 10, 2009. Romania's health authorities declared on Tuesday that 1001 people have been infected with the H1N1 virus since the first case in the Balkan country was reported in May. REUTERS/Bogdan Cristel (ROMANIA HEALTH EDUCATION) 

Children wear face masks for protection against the H1N1 flu virus at a school in Bucharest November 10, 2009. Romania's health authorities declared on Tuesday that 1001 people have been infected with the H1N1 virus since the first case in the Balkan country was reported in May. REUTERS/Bogdan Cristel (ROMANIA HEALTH EDUCATION) 

Children wear face masks for protection against the H1N1 flu virus at a school in Bucharest November 10, 2009. Romania's health authorities declared on Tuesday that 1001 people have been infected with the H1N1 virus since the first case in the Balkan country was reported in May. REUTERS/Bogdan Cristel (ROMANIA HEALTH EDUCATION) 

Children wear face masks for protection against the H1N1 flu virus at a school in Bucharest November 10, 2009. Romania's health authorities declared on Tuesday that 1001 people have been infected with the H1N1 virus since the first case in the Balkan country was reported in May. REUTERS/Bogdan Cristel (ROMANIA HEALTH IMAGES OF THE DAY) 

Children wear face masks for protection against the H1N1 flu virus at a school in Bucharest November 10, 2009. Romania's health authorities declared on Tuesday that 1001 people have been infected with the H1N1 virus since the first case in the Balkan country was reported in May. REUTERS/Bogdan Cristel (ROMANIA HEALTH) 

A woman receives an injection of the H1N1 flu vaccine in Lvovsky, 40 km (25 miles) south of Moscow, November 9, 2009. Russia launched a vaccination campaign against the H1N1 flu disease on Monday, local media reported. REUTERS/Yuri Maltsev (RUSSIA HEALTH) 

Riot police, wearing face masks against H1N1 flu, stand guard during a unionised workers' rally demanding better working conditions near the National Assembly in Seoul November 7, 2009. Tens of thousands of workers from the Federation of Korean Trade Unions, the less militant of South Korea's two umbrella labour organizations, held the rally on Saturday to denounce Lee Myung-bak government's labour policy. REUTERS/Jo Yong-Hak (SOUTH KOREA CONFLICT EMPLOYMENT BUSINESS) 

Unionised workers, wearing face masks against H1N1 flu, sit on a street while riot police, also wearing face masks, stand guard during a rally demanding their better working conditions near the National Assembly in Seoul November 7, 2009. Tens of thousands of workers from the Federation of Korean Trade Unions, the less militant of South Korea's two umbrella labour organizations, held the rally on Saturday to denounce Lee Myung-bak government's labour policy. The red headbands read, "Unity and Fighting". REUTERS/Jo Yong-Hak (SOUTH KOREA CONFLICT EMPLOYMENT BUSINESS) 

Dynamo Kiev's fans wear face masks as a preventive measure against the H1N1 flu as they attend their Champions League soccer match against Inter Milan in Kiev November 4, 2009. REUTERS/Gleb Garanich (UKRAINE SPORT SOCCER) 

Dynamo Kiev's fans wear face masks as a preventive measure against the H1N1 flu during their Champions League soccer match against Inter Milan in Kiev November 4, 2009. REUTERS/Gleb Garanich (UKRAINE SPORT SOCCER HEALTH) 

A man wearing a mask is reflected in the mirror window as he leaves a shop in the centre of the Siberian city of Krasnoyarsk, November 3, 2009. The H1N1 flu outbreak has already killed 10 Russian citizens, Interfax news agency reported. REUTERS/Ilya Naymushin (RUSSIA HEALTH IMAGES OF THE DAY) 

An Afghan boy wearing a protective face mask cycles on a street in Herat November 2, 2009. Afghanistan declared a health emergency on Monday to help the government prevent the rapid spread of H1N1 and ordered schools closed for three weeks as part of measures against the deadly virus. REUTERS/Morteza Nikoubazl (AFGHANISTAN HEALTH SOCIETY) 

An Afghan woman wears a protective face mask inside a hospital in Herat November 2, 2009. Afghanistan declared a health emergency on Monday to help the government prevent the rapid spread of H1N1 and ordered schools closed for three weeks as part of measures against the deadly virus. REUTERS/Morteza Nikoubazl (AFGHANISTAN HEALTH SOCIETY) 

Medical personnel wear protective face masks at a hospital in Herat November 2, 2009. Afghanistan declared a health emergency on Monday to help the government prevent the rapid spread of H1N1 and ordered schools closed for three weeks as part of measures against the deadly virus. REUTERS/Morteza Nikoubazl (AFGHANISTAN HEALTH SOCIETY) 

A cameraman wears a mask while reporting in front of a school closed by sanitary authorities due to a H1N1 virus infection among students in Bucharest November 2, 2009. Authorities have closed several schools recently due to the rapid spread of the H1N1 flu virus and boosted vaccine stockpile to face a potential pandemic more resolutely. REUTERS/Bogdan Cristel (ROMANIA HEALTH EDUCATION) 

Children wearing protective masks play in central square in the Ukrainian capital Kiev November 2, 2009. Ukraine closed schools and banned public meetings including election rallies and restricted travel last Friday for a three-week period after confirming its first death from H1N1 flu. REUTERS/Gleb Garanich (UKRAINE HEALTH) 

A boy wearing a protective mask is seen in the central square of Kiev November 2, 2009. Ukraine confirmed its first death from H1N1 swine flu on October 30 and officials said that a quarantine could be introduced to halt the spread of the virus. REUTERS/Gleb Garanich (UKRAINE HEALTH) 

Afghan school boys wearing face masks are pictured at the main market in Kabul, November 2, 2009. The Afghan government ordered closure of all educational institutions for a period of three weeks due to the dramatic rise of H1N1 flu cases and after its first death from the virus last week. REUTERS/Oleg Popov (AFGHANISTAN HEALTH SOCIETY EDUCATION) 

An Afghan student wearing a face mask walks at the main market in Kabul, November 2, 2009. The Afghan government ordered closure of all educational institutions for a period of three weeks due to the dramatic rise of H1N1 flu cases and after its first death from the virus last week. REUTERS/Oleg Popov (AFGHANISTAN HEALTH SOCIETY EDUCATION)