Students test themselves for coronavirus before starting lessons at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Students test themselves for coronavirus before starting lessons at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

A student tests herself for coronavirus before starting lessons at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Paula Luedecke, a student, wears a protective mask during a lesson at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

A student and a teacher wear protective masks during a lesson at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Paula Luedecke, a student, tests herself for coronavirus before starting lessons at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Students test themselves for coronavirus before starting lessons at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Students test themselves for coronavirus before starting lessons at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Students test themselves for coronavirus before starting lessons at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Students test themselves for coronavirus before starting lessons at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Students test themselves for coronavirus before starting lessons at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Students wear protective masks during a lesson at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Students wear protective masks during a lesson at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

A student tests themselves for Coronavirus before starting lessons at a grammar school in Dresden, Germany, November 18, 2021. REUTERS/Matthias Rietschel 

Shade Ajayi, 50, takes notes during class at Ilorin Grammar School in Ilorin, Kwara state, March 25, 2021. REUTERS/Temilade Adelaja/File Photo TPX IMAGES OF THE DAY SEARCH "GLOBAL POY" FOR THIS STORY. SEARCH "REUTERS POY" FOR ALL BEST OF 2021 PACKAGES. 

Shade Ajayi, 50, takes notes during class at Ilorin Grammar School in Ilorin, Kwara state, March 25, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES TPX IMAGES OF THE DAY 

Shade Ajayi, 50, chats to some of her classmates after class at Ilorin Grammar school in Ilorin, Kwara state, Nigeria, March 24, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES TPX IMAGES OF THE DAY 

Students stand on tyres in the playground of Ilorin Grammar school, in Ilorin, Kwara state, Nigeria, March 24, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Shade Ajayi, 50, looks at her classmates as they play outside after class at Ilorin Grammar School, Kwara state, March 25, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Shade Ajayi, 50, stands up during class at Ilorin Grammar School in Ilorin, Kwara state, March 25, 2021. Ajayi intends to continue her education for four more years, saying it will help her business. "People around me can read and write and they are succeeding in their businesses," she said. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Shade Ajayi, 50, raises her hand to answer a question during class at Ilorin Grammar School in Ilorin, Kwara state, March 25, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Shade Ajayi, 50, eats lunch in an empty calssroom at Ilorin Grammar School in Ilorin, Kwara state, March 24, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Shade Ajayi, 50, reads a book as she sits in the library at Ilorin Grammar School in Ilorin, Kwara state, March 24, 2021. Ajayi intends to continue her education for four more years, saying it will help her business. "People around me can read and write and they are succeeding in their businesses," she said. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Shade Ajayi, 50, is helped by a teacher at Ilorin Grammar School in Ilorin, Kwara state, March 24, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Shade Ajayi, 50, reads a book on mathematics in the library at Ilorin Grammar School, Kwara state, March 24, 2021. Ajayi intends to continue her education for four more years, saying it will help her business. "People around me can read and write and they are succeeding in their businesses," she said. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Joy Adeniji, 12, plays a game with her classmates after school at Ilorin Grammar school, Kwara state, Nigeria, March 26, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A teacher writes on a chalk board as she teaches a class at Ilorin Grammar School, in Ilorin, Kwara state, March 24, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Shade Ajayi, 50, changes into her school uniform before attending class at Ilorin Grammar School in Ilorin, Kwara state, March 24, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Quareebullahi Ajenifuja, 12, and Joy Adeniji, 12, take notes together during class at Ilorin Grammar school, in Ilorin, Kwara state, Nigeria, March 26, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Shade Ajayi, 50, takes notes during class at Ilorin Grammar School in Ilorin, Kwara state, March 24, 2021. REUTERS/Temilade Adelaja SEARCH "ADELAJA PUPIL" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Volunteers wait for students to arrive to take coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

Students talk with volunteers before taking a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

A student talks with a member of school staff before taking a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

Students talk with volunteers before taking a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

A volunteer waits to process the coronavirus disease (COVID-19) tests in the school hall before students return to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

A student takes a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

Students talk with volunteers before taking a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

Students talk with volunteers before taking a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

Testing bays are seen in the school hall ahead of the coronavirus disease (COVID-19) tests before students return to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

A student talks to a volunteer before taking a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

A student sanitises her hands before taking a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

A student talks to a school staff before taking a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

A student takes a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

Students talk with volunteers before taking a coronavirus disease (COVID-19) test in the school hall before returning to school at Loreto Grammar School in Altrincham, Britain, March 5, 2021. REUTERS/Phil Noble 

A student reacts as she checks her GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A student reacts as he checks his GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

The highest achieving students Harris, Gwen and Barney pose for a photograph in front of the school after achieving 11 Grade 9's in their GCSE results, at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A student checks her GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A mother of a student reacts as she checks his GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A student reacts after she received her GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A student reacts as she checks her GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A student checks his GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A student checks her GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

Students react as they check their GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A student reacts as she checks her GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A student reacts as he checks his GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A student checks his GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

A student reacts as she checks her GCSE results at Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 20, 2020. REUTERS/Molly Darlington 

Sixth form students are seen after receiving their A-Level results at The Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 13, 2020. REUTERS/Molly Darlington 

A sixth form student wearing a protective mask reacts after receiving her A-Level results at The Crossley Heath Grammar School, amid the spread of the coronavirus disease (COVID-19), in Halifax, Britain August 13, 2020. REUTERS/Molly Darlington