A security guard checks for proof of vaccination at the entrance to a food court during phase one of Ontario's vaccine certification program in Toronto, Ontario, Canada September 22, 2021. REUTERS/Carlos Osorio

A security guard checks for proof of vaccination at the entrance to a food court during phase one of Ontario's vaccine certification program in Toronto, Ontario, Canada September 22, 2021. REUTERS/Carlos Osorio

U.S. President Joe Biden hosts a virtual coronavirus disease (COVID-19) Summit as part of the United Nations General Assembly (UNGA) from the White House in Washington, U.S., September 22, 2021.REUTERS/Evelyn Hockstein

A security guard checks for proof of vaccination at the entrance to a food court during phase one of Ontario's vaccine certification program in Toronto, Ontario, Canada September 22, 2021. REUTERS/Carlos Osorio

Lebanese singer Majida El Roumi performs during the opening of Jerash Festival of Culture and Arts, after a one-year suspension due to the outbreak of the coronavirus disease (COVID-19), in the ancient city of Jerash, Jordan September 22, 2021. REUTERS/Alaa Al Sukhni

Lebanese singer Majida El Roumi performs during the opening of Jerash Festival of Culture and Arts, after a one-year suspension due to the outbreak of the coronavirus disease (COVID-19), in the ancient city of Jerash, Jordan September 22, 2021. REUTERS/Alaa Al Sukhni

Lebanese singer Majida El Roumi performs during the opening of Jerash Festival of Culture and Arts, after a one-year suspension due to the outbreak of the coronavirus disease (COVID-19), in the ancient city of Jerash, Jordan September 22, 2021. REUTERS/Alaa Al Sukhni

Lebanese singer Majida El Roumi performs during the opening of Jerash Festival of Culture and Arts, after a one-year suspension due to the outbreak of the coronavirus disease (COVID-19), in the ancient city of Jerash, Jordan September 22, 2021. REUTERS/Alaa Al Sukhni

Mongolian President Ukhnaa Khurelsukh takes off his protective face mask worn due to the coronavirus disease (COVID-19) pandemic as he arrives to speak at the 76th Session of the U.N. General Assembly in New York City, U.S., September 22, 2021. REUTERS/Eduardo Munoz/Pool

Brazil's President Jair Bolsonaro puts back on a protective face mask worn due to the coronavirus disease (COVID-19) pandemic after speaking during the 76th Session of the U.N. General Assembly in New York City, U.S., September 21, 2021. REUTERS/Eduardo Munoz/Pool

Brazil's President Jair Bolsonaro walks outside his hotel while attending the UN General Assembly 76th session General Debate at the United Nations, in New York City, U.S., September 20, 2021. REUTERS/Stefan Jeremiah

Dancers perform during the opening of Jerash Festival of Culture and Arts, after a one-year suspension due to the outbreak of the coronavirus disease (COVID-19), in the ancient city of Jerash, Jordan September 22, 2021. REUTERS/Alaa Al Sukhni

Children perform during the opening of Jerash Festival of Culture and Arts, after a one-year suspension due to the outbreak of the coronavirus disease (COVID-19), in the ancient city of Jerash, Jordan September 22, 2021. REUTERS/Alaa Al Sukhni

People arrive to attend the opening of Jerash Festival of Culture and Arts, after a one-year suspension due to the outbreak of the coronavirus disease (COVID-19), in the ancient city of Jerash, Jordan September 22, 2021. REUTERS/Alaa Al Sukhni

Security members wearing protective face masks stand guard during the opening of Jerash Festival of Culture and Arts, after a one-year suspension due to the outbreak of the coronavirus disease (COVID-19), in the ancient city of Jerash, Jordan September 22, 2021. REUTERS/Alaa Al Sukhni

Artists perform during the opening of Jerash Festival of Culture and Arts, after a one-year suspension due to the outbreak of the coronavirus disease (COVID-19), in the ancient city of Jerash, Jordan September 22, 2021. REUTERS/Alaa Al Sukhni

An empty bed sits in a room where a coronavirus disease (COVID-19) positive patient died on Tuesday, on the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

Critical Care Respiratory therapist Lauren Parsons collects a blood sample from a coronavirus disease (COVID-19) positive patient in their isolation room on the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

Critical Care Respiratory therapist Lauren Parsons treats a coronavirus disease (COVID-19) positive patient in their isolation room on the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

U.S. Vice President Kamala Harris leads a session of the President's online COVID Summit inside the Eisenhower Executive Office Building at the White House in Washington, U.S., September 22, 2021. REUTERS/Tom Brenner

Critical Care Respiratory therapist Lauren Parsons looks at a coronavirus disease (COVID-19) positive patient in their isolation room on the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

U.S. Vice President Kamala Harris leads a session of the President's online COVID Summit inside the Eisenhower Executive Office Building at the White House in Washington, U.S., September 22, 2021. REUTERS/Tom Brenner

U.S. Vice President Kamala Harris leads a session of the President's online COVID Summit inside the Eisenhower Executive Office Building at the White House in Washington, U.S., September 22, 2021. REUTERS/Tom Brenner

U.S. Vice President Kamala Harris leads a session of the President's online COVID Summit inside the Eisenhower Executive Office Building at the White House in Washington, U.S., September 22, 2021. REUTERS/Tom Brenner

U.S. Vice President Kamala Harris leads a session of the President's online COVID Summit inside the Eisenhower Executive Office Building at the White House in Washington, U.S., September 22, 2021. REUTERS/Tom Brenner

Critical Care Respiratory therapist Lauren Parsons treats a coronavirus disease (COVID-19) positive patient in their isolation room on the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

Critical Care Respiratory therapist Lauren Parsons looks down before entering the isolation room of a coronavirus disease (COVID-19) positive patient on the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

Housekeeper Maura Otero, 56, cleans the room of a coronavirus disease (COVID-19) positive patient inside his isolation room in the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

Members of a Covid critical care unit treat a coronavirus disease (COVID-19) positive patient inside his isolation room in the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

Members of a Covid critical care unit treat a coronavirus disease (COVID-19) positive patient inside his isolation room in the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

Critical Care Respiratory therapist Lauren Parsons reaches out of the isolation room of a coronavirus disease (COVID-19) positive patient on the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

Critical Care Respiratory therapist Lauren Parsons treats a coronavirus disease (COVID-19) positive patient in their isolation room on the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida, U.S., September 22, 2021. REUTERS/Shannon Stapleton

A man waits to enter a mobile vaccination facility run by transit agency Metrolinx and the province of Ontario in Ajax, Ontario, Canada, September 22, 2021. REUTERS/Chris Helgren

A sign is lit at the front of a bus serving as a mobile vaccination facility run by transit agency Metrolinx and the province of Ontario in Ajax, Ontario, Canada, September 22, 2021. REUTERS/Chris Helgren

U.S. President Joe Biden and U.S. Ambassador to the United Nations Linda Thomas-Greenfield participate in a virtual coronavirus disease (COVID-19) Summit as part of the United Nations General Assembly (UNGA) from the South Court Auditorium in the White House complex in Washington, U.S., September 22, 2021. REUTERS/Evelyn Hockstein

U.S. President Joe Biden and U.S. Ambassador to the United Nations Linda Thomas-Greenfield participate in a virtual coronavirus disease (COVID-19) Summit as part of the United Nations General Assembly (UNGA) from the South Court Auditorium in the White House complex in Washington, U.S., September 22, 2021. REUTERS/Evelyn Hockstein

U.S. President Joe Biden and U.S. Ambassador to the United Nations Linda Thomas-Greenfield participate in a virtual coronavirus disease (COVID-19) Summit as part of the United Nations General Assembly (UNGA) from the South Court Auditorium in the White House complex in Washington, U.S., September 22, 2021. REUTERS/Evelyn Hockstein

A visitor attends the Chelsea Flower Show, delayed from its usual spring dates because of lockdown restrictions amid the spread of the coronavirus disease (COVID-19) pandemic in London, Britain, September 22, 2021. REUTERS/Hannah McKay

A visitor attends the Chelsea Flower Show, delayed from its usual spring dates because of lockdown restrictions amid the spread of the coronavirus disease (COVID-19) pandemic in London, Britain, September 22, 2021. REUTERS/Hannah McKay

A stall worker tends to a rose garden at the Chelsea Flower Show, delayed from its usual spring dates because of lockdown restrictions amid the spread of the coronavirus disease (COVID-19) pandemic in London, Britain, September 22, 2021. REUTERS/Hannah McKay

A visitor attends the Chelsea Flower Show, delayed from its usual spring dates because of lockdown restrictions amid the spread of the coronavirus disease (COVID-19) pandemic in London, Britain, September 22, 2021. REUTERS/Hannah McKay

A visitor attends the Chelsea Flower Show, delayed from its usual spring dates because of lockdown restrictions amid the spread of the coronavirus disease (COVID-19) pandemic in London, Britain, September 22, 2021. REUTERS/Hannah McKay

A visitor attends the Chelsea Flower Show, delayed from its usual spring dates because of lockdown restrictions amid the spread of the coronavirus disease (COVID-19) pandemic in London, Britain, September 22, 2021. REUTERS/Hannah McKay

Visitors attend the Chelsea Flower Show, delayed from its usual spring dates because of lockdown restrictions amid the spread of the coronavirus disease (COVID-19) pandemic in London, Britain, September 22, 2021. REUTERS/Hannah McKay

A visitor attends the Chelsea Flower Show, delayed from its usual spring dates because of lockdown restrictions amid the spread of the coronavirus disease (COVID-19) pandemic in London, Britain, September 22, 2021. REUTERS/Hannah McKay

Visitors attend the Chelsea Flower Show, delayed from its usual spring dates because of lockdown restrictions amid the spread of the coronavirus disease (COVID-19) pandemic in London, Britain, September 22, 2021. REUTERS/Hannah McKay

A visitor attends the Chelsea Flower Show, delayed from its usual spring dates because of lockdown restrictions amid the spread of the coronavirus disease (COVID-19) pandemic in London, Britain, September 22, 2021. REUTERS/Hannah McKay

A doctor takes a shot with a smartphone of an X-ray image of a patient suffering from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

Medical workers treat a patient suffering from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

Medical worker checks an X-ray image of a patient suffering from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

Patient suffers from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

Medical workers prepare to take an X-ray image of a patient suffering from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

A medical worker prepares to take an X-ray image of a patient suffering from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

A patient suffers from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

Medical worker takes a break on a balcony of the intensive care unit at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

A nurse checks the treatment for a patient suffering from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

Medical worker treat a patient suffering from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

A nurse prepares to feed intubated patient suffering from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

A nurse feeds an intubated patient suffering from coronavirus disease (COVID-19) in the intensive care unit (ICU) at the Clinical Center of Montenegro in Podgorica September 22, 2021. REUTERS/Stevo Vasiljevic

Health Minister Jens Spahn (CDU) addresses the media during a statement on the coronavirus disease (COVID-19) situation in Berlin, Germany, September 22, 2021. REUTERS/Michele Tantussi