Pupils attend a class at Ysgol Hafan Y Mor school following the coronavirus (COVID-19) lockdown in Tenby, Wales, Britain February 26, 2021. REUTERS/Rebeca Naden

Pupils hang their clothes in a hallway of Ysgol Hafan Y Mor school following the coronavirus (COVID-19) lockdown in Tenby, Wales, Britain February 26, 2021. REUTERS/Rebeca Naden

Pupils attend a class at Ysgol Hafan Y Mor school following the coronavirus (COVID-19) lockdown in Tenby, Wales, Britain February 26, 2021. REUTERS/Rebeca Naden

Pupils attend a class at Ysgol Hafan Y Mor school following the coronavirus (COVID-19) lockdown in Tenby, Wales, Britain February 26, 2021. REUTERS/Rebeca Naden

Pupils attend a class at Ysgol Hafan Y Mor school following the coronavirus (COVID-19) lockdown in Tenby, Wales, Britain February 26, 2021. REUTERS/Rebeca Naden

Mila and Ashton Carruthers react as they prepare to return at Pitlochry High School on the first day back following the easing of the coronavirus disease (COVID-19) restrictions, in Pitlochry, Scotland, Britain, February 22, 2021. REUTERS/Russell Cheyne

Mila Carruthers is reflected in a mirror as she prepares to return at Pitlochry High School on the first day back following the easing of the coronavirus disease (COVID-19) restrictions, in Pitlochry, Scotland, Britain, February 22, 2021. REUTERS/Russell Cheyne

Ashton Carruthers looks on as he and his sister Mila prepare to return at Pitlochry High School on the first day back following the easing of the coronavirus disease (COVID-19) restrictions, in Pitlochry, Scotland, Britain, February 22, 2021. REUTERS/Russell Cheyne

Mila and Ashton Carruthers put their shoes on as they prepare to return at Pitlochry High School on the first day back following the easing of the coronavirus disease (COVID-19) restrictions, in Pitlochry, Scotland, Britain, February 22, 2021. REUTERS/Russell Cheyne

Ashton Carruthers reacts as he prepares to return at Pitlochry High School on the first day back following the easing of the coronavirus disease (COVID-19) restrictions, in Pitlochry, Scotland, Britain, February 22, 2021. REUTERS/Russell Cheyne

Mila Carruthers reacts as she prepares to return at Pitlochry High School on the first day back following the easing of the coronavirus disease (COVID-19) restrictions, in Pitlochry, Scotland, Britain, February 22, 2021. REUTERS/Russell Cheyne

Pupils walk to Pitlochry High School on the first day back following the easing of the coronavirus disease (COVID-19) restrictions, in Pitlochry, Scotland, Britain, February 22, 2021. REUTERS/Russell Cheyne

Pupils walk to Pitlochry High School on the first day back following the easing of the coronavirus disease (COVID-19) restrictions, in Pitlochry, Scotland, Britain, February 22, 2021. REUTERS/Russell Cheyne

A view of shelves during preparations for the return of pupils on Monday at Pitlochry High School, Pitlochry Scotland, Britain, February 19, 2021. REUTERS/Russell Cheyne

A view of school supplies during preparations for the return of pupils on Monday at Pitlochry High School, Pitlochry Scotland, Britain, February 19, 2021. REUTERS/Russell Cheyne

General view of a hallway during preparations for the return of pupils on Monday at Pitlochry High School, Pitlochry Scotland, Britain, February 19, 2021. REUTERS/Russell Cheyne

General view of the schoolyard during preparations for the return of pupils on Monday at Pitlochry High School, Pitlochry Scotland, Britain, February 19, 2021. REUTERS/Russell Cheyne

General view of the schoolyard during preparations for the return of pupils on Monday at Pitlochry High School, Pitlochry Scotland, Britain, February 19, 2021. REUTERS/Russell Cheyne

Staff make preparations for the return of pupils on Monday at Pitlochry High School, Pitlochry Scotland, Britain, February 19, 2021 REUTERS/Russell Cheyne

Staff make preparations for the return of pupils on Monday at Pitlochry High School, Nursery, Pitlochry Scotland, Britain, February 19, 2021 REUTERS/Russell Cheyne

Staff make preparations for the return of pupils on Monday at Pitlochry High School, Nursery, Pitlochry Scotland, Britain, February 19, 2021 REUTERS/Russell Cheyne

Staff make preparations for the return of pupils on Monday at Pitlochry High School, Nursery, Pitlochry Scotland, Britain, February 19, 2021 REUTERS/Russell Cheyne

Staff make preparations for the return of pupils on Monday at Pitlochry High School, Nursery, Pitlochry Scotland, Britain, February 19, 2021 REUTERS/Russell Cheyne

Staff make preparations for the return of pupils on Monday at Pitlochry High School, Nursery, Pitlochry Scotland, Britain, February 19, 2021 REUTERS/Russell Cheyne

Staff make preparations for the return of pupils on Monday at Pitlochry High School, Nursery, Pitlochry Scotland, Britain, February 19, 2021 REUTERS/Russell Cheyne

Staff make preparations for the return of pupils on Monday at Pitlochry High School, Nursery, Pitlochry Scotland, Britain, February 19, 2021 REUTERS/Russell Cheyne

Staff make preparations for the return of pupils on Monday at Pitlochry High School, Nursery, Pitlochry Scotland, Britain, February 19, 2021 REUTERS/Russell Cheyne

Teachers pass the mid-year report and a burger to their pupils during their "burger and reports"-drive-through event as the spread of the coronavirus disease (COVID-19) continues during an extended lockdown at the "Freie Montessori Schule" (free Montessori school) in Geislitz near Frankfurt, Germany, February 1, 2021. REUTERS/Kai Pfaffenbach

Teachers wait for their pupils to pick up their mid-year reports and a burger in their "burger and reports"-drive through event as the spread of the coronavirus disease (COVID-19) continues during an extended lockdown at the "Freie Montessori Schule" (free Montessori school) in Geislitz near Frankfurt, Germany, February 1, 2021. REUTERS/Kai Pfaffenbach

Teachers pass the mid-year report and a burger to one of their pupils during their "burger and reports"-drive through event as the spread of the coronavirus disease (COVID-19) continues during an extended lockdown at the "Freie Montessori Schule" (free Montessori school) in Geislitz near Frankfurt, Germany, February 1, 2021. REUTERS/Kai Pfaffenbach

Teachers wait for their pupils to pick up their mid-year reports and a burger in their "burger and reports"-drive through event as the spread of the coronavirus disease (COVID-19) continues during an extended lockdown at the "Freie Montessori Schule" (free Montessori school) in Geislitz near Frankfurt, Germany, February 1, 2021. REUTERS/Kai Pfaffenbach

Teachers wait for their pupils to pick up their mid-year reports and a burger in their "burger and reports"-drive through event as the spread of the coronavirus disease (COVID-19) continues during an extended lockdown, at the "Freie Montessori Schule" (free Montessori school) in Geislitz near Frankfurt, Germany, February 1, 2021. REUTERS/Kai Pfaffenbach

Teachers wait for their pupils to pick up their mid-year reports and a burger in their "burger and reports"-drive through event during an extended lockdown as the spread of the coronavirus disease (COVID-19) continues, at the "Freie Montessori Schule" (free Montessori school) in Geislitz near Frankfurt, Germany, February 1, 2021. REUTERS/Kai Pfaffenbach

Primary school teacher Marzio Toniolo's pupils watch an animation as they return to the classroom as part of Italy's coronavirus disease (COVID-19) regulations after the holidays, in Santo Stefano Lodigiano, Italy, January 7, 2021. Toniolo has been documenting what life has been like for a small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country in February last year. REUTERS/Marzio Toniolo

Primary school teacher Marzio Toniolo's pupils, wearing masks, sit at a distance apart from each other during a lesson as they return to the classroom as part of Italy's coronavirus disease (COVID-19) regulations after the holidays, in Santo Stefano Lodigiano, Italy, January 7, 2021. Toniolo has been documenting what life has been like for a small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country in February last year. REUTERS/Marzio Toniolo

Primary school teacher Marzio Toniolo's pupils, wearing masks, sitting at a distance from each other attend a lesson as they return to the classroom as part of Italy's coronavirus disease (COVID-19) regulations after the holidays, in Santo Stefano Lodigiano, Italy, January 7, 2021. Toniolo has been documenting what life has been like for a small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country in February last year. REUTERS/Marzio Toniolo TPX IMAGES OF THE DAY

Primary school teacher Marzio Toniolo's pupil William Xhafa wears a mask as children return to the classroom as part of Italy's coronavirus disease (COVID-19) regulations after the holidays, in Santo Stefano Lodigiano, Italy, January 7, 2021. Toniolo has been documenting what life has been like for a small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country in February last year. REUTERS/Marzio Toniolo

Banner reads, "The school is open!!", at the entrance of a primary school as schoolchildren return to the classroom as part of Italy's COVID-19 regulations after the Christmas holidays, while older pupils continue their studies online, in Maleo, one of Lombardy's original 'red zone' towns January 7, 2021. Schoolteacher Toniolo has been documenting what life has been like for a small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country in February last year. REUTERS/Marzio Toniolo

Primary schoolchildren return to the classroom as part of Italy's coronavirus disease (COVID-19) regulations after the Christmas holidays, while older pupils continue their studies online, in Maleo, one of Lombardy's original 'red zone' towns January 7, 2021. Schoolteacher Toniolo has been documenting what life has been like for a small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country in February last year. REUTERS/Marzio Toniolo

Elementary schoolchildren return to the classroom as part of Italy's coronavirus disease (COVID-19) regulations after the Christmas holidays, while older pupils continue their studies online, in Maleo, one of Lombardy's original 'red zone' towns January 7, 2021. Schoolteacher Toniolo has been documenting what life has been like for a small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country in February last year. REUTERS/Marzio Toniolo

Primary schoolchildren enter a classroom as they return to school as part of Italy's coronavirus disease (COVID-19) regulations after the Christmas holidays, while older pupils continue their studies online, in Maleo, one of Lombardy's original 'red zone' towns January 7, 2021. Schoolteacher Toniolo has been documenting what life has been like for a small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country in February last year. REUTERS/Marzio Toniolo

Primary schoolchildren stand in groups in a school courtyard as they return to the classroom as part of Italy's coronavirus disease (COVID-19) regulations after the Christmas holidays, while older pupils continue their studies online, in Maleo, one of Lombardy's original 'red zone' towns January 7, 2021. Schoolteacher Toniolo has been documenting what life has been like for a small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country in February last year. REUTERS/Marzio Toniolo

Teacher Claudia Mohme from the Freiherr-vom-Stein secondary school in the North Rhine-Westphalian city of Bonn conducts a lesson for just two pupils amid the coronavirus disease (COVID-19) pandemic in Bonn, Germany, December 14, 2020. REUTERS/Wolfgang Rattay

Teacher Claudia Mohme from the Freiherr-vom-Stein secondary school in the North Rhine-Westphalian city of Bonn conducts a lesson for just two pupils amid the coronavirus disease (COVID-19) pandemic in Bonn, Germany, December 14, 2020. REUTERS/Wolfgang Rattay

Teacher Claudia Mohme from the Freiherr-vom-Stein secondary school in the North Rhine-Westphalian city of Bonn conducts a lesson for just two pupils amid the coronavirus disease (COVID-19) pandemic in Bonn, Germany, December 14, 2020. REUTERS/Wolfgang Rattay

Britain's Catherine, Duchess of Cambridge smiles during a meet with staff and pupils from Holy Trinity Church of England First School in Berwick-Upon-Tweed, Britain as part of her working visits across the UK ahead of the Christmas holidays to pay tribute to the work of individuals and organisations across the country in response to the coronavirus pandemic December 7, 2020. Andy Commins/Pool via REUTERS

Britain's Catherine, Duchess of Cambridge meets pupils from Holy Trinity Church of England First School in Berwick-Upon-Tweed, Britain as part of her working visits across the UK ahead of the Christmas holidays to pay tribute to the work of individuals and organisations across the country in response to the coronavirus pandemic December 7, 2020. Andy Commins/Pool via REUTERS

Britain's Prince William and Catherine, Duchess of Cambridge meet staff and pupils from Holy Trinity Church of England First School in Berwick-Upon-Tweed, Britain as part of their working visits across the UK ahead of the Christmas holidays to pay tribute to the work of individuals and organisations across the country in response to the coronavirus pandemic December 7, 2020. Andy Commins/Pool via REUTERS

Britain's Prince William and Catherine, Duchess of Cambridge meet staff and pupils from Holy Trinity Church of England First School in Berwick-Upon-Tweed, Britain as part of their working visits across the UK ahead of the Christmas holidays to pay tribute to the work of individuals and organisations across the country in response to the coronavirus pandemic December 7, 2020. Andy Commins/Pool via REUTERS

Britain's Prince William and Catherine, Duchess of Cambridge meet pupils from Holy Trinity Church of England First School in Berwick-Upon-Tweed, Britain as part of their working visits across the UK ahead of the Christmas holidays to pay tribute to the work of individuals and organisations across the country in response to the coronavirus pandemic December 7, 2020. Andy Commins/Pool via REUTERS

Britain's Prince William and Catherine, Duchess of Cambridge meet pupils from Holy Trinity Church of England First School in Berwick-Upon-Tweed, Britain as part of their working visits across the UK ahead of the Christmas holidays to pay tribute to the work of individuals and organisations across the country in response to the coronavirus pandemic December 7, 2020. Andy Commins/Pool via REUTERS

Britain's Prince William and Catherine, Duchess of Cambridge meet staff and pupils from Holy Trinity Church of England First School in Berwick-Upon-Tweed, Britain as part of their working visits across the UK ahead of the Christmas holidays to pay tribute to the work of individuals and organisations across the country in response to the coronavirus pandemic December 7, 2020. Andy Commins/Pool via REUTERS

Andreas Tempel, director of the Alexander Coppel Gesamtschule school is seen during the spread of the coronavirus disease (COVID-19) in Solingen, Germany November 17, 2020. Tempel and his school became well known in Germany because the administration of the federal state of North-Rhine Westphalia disallowed the school to reduce the amount of pupils by splitting the lessons into half virtual from home and the other half through normal presence lessons. REUTERS/Wolfgang Rattay

Andreas Tempel, director of Alexander Coppel Gesamtschule school holds a lesson during the spread of the coronavirus disease (COVID-19) in Solingen, Germany November 17, 2020. Tempel and his school became well known in Germany because the administration of the federal state of North-Rhine Westphalia disallowed the school to reduce the amount of pupils by splitting the lessons into half virtual from home and the other half through normal presence lessons. REUTERS/Wolfgang Rattay

Pupils attend a virtual English lesson held by teacher Tobias Honnen, who stays in home quarantine after contact with an infected pupil during sports lessons, at Alexander Coppel Gesamtschule school during the spread of the coronavirus disease (COVID-19) in Solingen, Germany November 17, 2020. REUTERS/Wolfgang Rattay

Pupils attend a virtual English lesson held by teacher Tobias Honnen, who stays in home quarantine after contact with an infected pupil during sports lessons, at Alexander Coppel Gesamtschule school during the spread of the coronavirus disease (COVID-19) in Solingen, Germany November 17, 2020. REUTERS/Wolfgang Rattay

Teacher Eike Postler holds a tablet computer on which quarantined teacher Tobias Honnen is seen from his home office during a virtual English lesson, at Alexander Coppel Gesamtschule school during the spread of the coronavirus disease (COVID-19) in Solingen, Germany November 17, 2020. Honnen, who has not been tested positive for COVID-19, stays in quarantine after contact with an infected pupil during sports lessons. REUTERS/Wolfgang Rattay

Teacher Eike Postler holds a tablet computer on which quarantined teacher Tobias Honnen is seen from his home office during a virtual English lesson, at Alexander Coppel Gesamtschule school during the spread of the coronavirus disease (COVID-19) in Solingen, Germany November 17, 2020. Honnen, who has not been tested positive for COVID-19, stays in quarantine after contact with an infected pupil during sports lessons. REUTERS/Wolfgang Rattay

Teacher Eike Postler holds a tablet computer on which quarantined teacher Tobias Honnen is seen from his home office during a virtual English lesson, at Alexander Coppel Gesamtschule school during the spread of the coronavirus disease (COVID-19) in Solingen, Germany November 17, 2020. Honnen, who has not been tested positive for COVID-19, stays in quarantine after contact with an infected pupil during sports lessons. REUTERS/Wolfgang Rattay