A year 7 student takes a COVID-19 lateral flow test on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

A lateral test is seen as Nicky Clough visits her mother Pam Harrison (both not pictured) in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

A sign hangs on the door as Nicky Clough (not pictured) visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Year 9 students wear protective face masks as they take part in lessons on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Principal, James Fisher, delivers his school welcome back assembly on a livestream from his office on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students wear protective face masks as they walk between classrooms on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

COVID-19 lateral flow tests are prepared for pupils on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Nicky Clough takes a swab for a lateral flow test before being allowed to visit her mother Pam Harrison at the Alexander House Care Home, as the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough has her temperature checked by care worker Terence Surin before entering the Alexander House Care Home to visit her mother Pam Harrison, as the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

A message is seen by students during a live-streamed assembly on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students wear protective face masks as they take part in lessons on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Social distancing signs are seen on a classroom door on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 7 students are instructed on how to take a lateral flow COVID-19 test on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students wear protective face masks as they walk between classrooms on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students wear protective face masks as they take part in a music lesson on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students wear protective face masks as they take part in a music lesson on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Year 9 students relax during break time on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students relax during break time on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students return to lessons following break time on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students return to lessons following break time on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students relax during break time on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students relax during break time on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

A year 9 student wears a protective face mask as he takes part in a music lesson on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students wear protective face masks as they take part in lessons on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Principal, James Fisher, delivers his school welcome back assembly on a livestream from his office on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

A year 7 student takes a COVID-19 lateral flow test on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students react as they speak with Principal, James Fisher, on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Year 9 students wear protective face masks as they take part in a music lesson on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

Students arrive for the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease, at Fulham Boys School in London, Britain, March 8, 2021. REUTERS/Kevin Coombs

Students arrive for the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease, at Fulham Boys School in London, Britain, March 8, 2021. REUTERS/Kevin Coombs

A teacher hands out face masks to students on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease, at Fulham Boys School in London, Britain, March 8, 2021. REUTERS/Kevin Coombs

Students assemble on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease, at Fulham Boys School in London, Britain, March 8, 2021. REUTERS/Kevin Coombs

Students arrive for the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease, at Fulham Boys School in London, Britain, March 8, 2021. REUTERS/Kevin Coombs

Students arrive for the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease, at Fulham Boys School in London, Britain, March 8, 2021. REUTERS/Kevin Coombs

Students arrive for the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease, at Fulham Boys School in London, Britain, March 8, 2021. REUTERS/Kevin Coombs

Students assemble on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease, at Fulham Boys School in London, Britain, March 8, 2021. REUTERS/Kevin Coombs

Students assemble on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease, at Fulham Boys School in London, Britain, March 8, 2021. REUTERS/Kevin Coombs

Paige Drobny's team at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness to help slow the spread of coronavirus disease (COVID-19), in Willow, Alaska, U.S. March 7, 2021. REUTERS/Nathaniel Wilder

Sean Underwood's team runs at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Sean Underwood's team runs at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Victoria Hardwick, the final musher to leave the start, participates at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Travis Beals' team runs at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Christopher Parker, a rookie, gestures at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Paige Drobny participates at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Jessie Holmes' team runs at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Aaron Burmeister heads down the trail at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Aaron Burmeister's team runs at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Wade Marrs' team runs at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Mille Porsild's team runs at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Susannah Tuminelli's team runs at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Matthew Failor's team runs at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Dogs in Aliy Zirkle's team runs at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder

Former champion Martin Buser and his team participate at the beginning of the Iditarod dog sled race, which is being held in a closed loop through the wilderness due to the coronavirus disease (COVID-19) pandemic, in Willow, Alaska, U.S., March 7, 2021. Picture taken March 7, 2021. REUTERS/Nathaniel Wilder