Some 37 million children in Bangladesh had their education disrupted by one of the world's longest pandemic school closures, says Unicef.
While schools reopened in September 2021, the government announced a new school closure from 23 January till 6 February this year.
"Closing schools must be a temporary measure of last resort in the Covid-19 response. Schools should be among the last institutions to close, and among the first to reopen, as we put in measures to tackle infection waves," said Sheldon Yett, Unicef representative to Bangladesh.
According to the global body, more than 635 million students remain affected by full or partial school closures.
On the International Day of Education and as the Covid-19 pandemic nears its two-year mark, Unicef shared the latest available data on the impact of the pandemic on children's learning, reads a press release.
"In March, we will mark two years of Covid-19-related disruptions to global education. Quite simply, we are looking at a nearly insurmountable scale of loss to children's schooling," said Robert Jenkins, Unicef chief of Education.
"While the disruptions to learning must end, just reopening schools is not enough. Students need intensive support to recover lost education. Schools must also go beyond places of learning to rebuild children's mental and physical health, social development and nutrition", he added.
Children have lost basic numeracy and literacy skills. Globally, disruption to education has meant millions of children have significantly missed out on the academic learning they would have acquired if they had been in the classroom, with younger and more marginalised children facing the greatest loss, added the statement.
In low- and middle-income countries, learning losses to school closures have left up to 70% of 10-year-olds unable to read or understand a simple text, up from 53% pre-pandemic.
A growing body of evidence shows that Covid-19 has caused high rates of anxiety and depression among children and young people, with some studies finding that girls, adolescents and those living in rural areas are most likely to experience these problems.
More than 370 million children globally missed out on school meals during school closures, losing what is for some children the only reliable source of food and daily nutrition.