Students wait in a queue as their friend receives a dose of the Moderna vaccine against the coronavirus disease (COVID-19), at their school during a vaccination drive for children aged 12-17 in Bhaktapur, Nepal, January 9, 2022.

Schoolchildren, wearing protective face masks, work in a classroom at the College Jean Renoir Middle School in Boulogne-Billancourt, near Paris, France, January 7, 2022.

Students of Kakungulu Memorial Secondary school attend a class, after schools reopened following the coronavirus disease (COVID-19) induced shutdown, in Kibuli suburb of Kampala, Uganda, January 10, 2022.

Students use computers on the day classes restart at the I.T.C Di Vittorio - I.T.I. Lattanzio secondary school as coronavirus disease (COVID-19) cases surge across the country and with new rules in place as part of the government's efforts to maintain in-person learning, in Rome, Italy, January 10, 2022.

Students sit in the classroom, as returning to schools with coronavirus disease (COVID-19) prevention measures began, in San Antonio, Texas, U.S., January 11, 2022.

Primary seven pupils sit inside their classroom at the Sweswe Primary School after schools reopened following the coronavirus disease (COVID-19) induced shutdown in Kyaka II Refugee Settlement, in Kyegegwa District, Uganda January 11, 2022.

High school students leave the Fiorello H. La Guardia High School as some students in New York City staged a walkout to urge officials to offer remote learning options due to concerns over safety amid the spread of the coronavirus disease (COVID-19) in Manhattan in New York City, New York, U.S., January 11, 2022.

Pupils queue at the Sweswe Primary School after schools reopened following the coronavirus disease (COVID-19) induced shutdown in Kyaka II Refugee Settlement, in Kyegegwa District, Uganda January 11, 2022.

Pupils at The Fulham Boys School take a mock exam on the first day after the Christmas holidays following a government announcement that face masks are to be worn in English secondary schools amid the coronavirus disease (COVID-19) outbreak in London, Britain, January 4, 2022.

Teacher Oscar Peret, 40, wears a protective face mask as he speaks to students in Salesia de Sant Josep school after the Christmas break, amid the coronavirus disease (COVID-19) surge in Barcelona, Spain January 10, 2022.

Students wearing protective masks, study in a classroom at the Merlan school in Paillet where, according to the director of the Pasteur Institut of Ivory Coast, professor Mireille Dosso, cases of the new Omicron variant of SARS-CoV-2 were detected, amid the outbreak of the coronavirus disease (COVID-19) in Abidjan, Cote d'Ivoire January 11, 2022. REUTERS / Luc Gnago

Students register and have their temperatures taken at Bukere Secondary School, after schools reopened following the coronavirus disease (COVID-19) induced shutdown in Kyaka II Refugee Settlement, in Kyegegwa District, Uganda January 11, 2022.

Students return to school with coronavirus disease (COVID-19) prevention measures in place in San Antonio, Texas, U.S., January 11, 2022.

A student wearing a protective mask, studies in a classroom at the Merlan school in Paillet where, according to the director of the Pasteur Institut of Ivory Coast, professor Mireille Dosso, cases of the new Omicron variant of SARS-CoV-2 were detected, amid the outbreak of the coronavirus disease (COVID-19) in Abidjan, Cote d'Ivoire January 11, 2022.

Students sit in a classroom on the day classes restart at the I.T.C Di Vittorio - I.T.I. Lattanzio secondary school as coronavirus disease (COVID-19) cases surge across the country and with new rules in place as part of the government's efforts to maintain in-person learning, in Rome, Italy, January 10, 2022.

A school worker applies hand sanitizer to students' hands as they return to school after the Christmas holidays as Portugal experiences a surge in coronavirus disease (COVID-19) cases due to the Omicron variant in Lisbon, Portugal, January 10, 2022.

Students wearing protective masks, study in a classroom at the Merlan school in Paillet where, according to the director of the Pasteur Institut of Ivory Coast, professor Mireille Dosso, cases of the new Omicron variant of SARS-CoV-2 were detected, amid the outbreak of the coronavirus disease (COVID-19) in Abidjan, Cote d'Ivoire January 11, 2022.

Primary seven pupils sit inside their classroom at the Sweswe Primary School after schools reopened following the coronavirus disease (COVID-19) induced shutdown in Kyaka II Refugee Settlement, in Kyegegwa District, Uganda January 11, 2022.

Students attend a class, as returning to schools with coronavirus disease (COVID-19) prevention measures began, in San Antonio, Texas, U.S., January 11, 2022.

Students return to school with coronavirus disease (COVID-19) prevention measures in place, in San Antonio, Texas, U.S., January 11, 2022.