Speaking on BBC Breakfast, Prof Leitch said that education is probably “the most important thing we have to try to keep open across the UK” in the coming weeks and months as experts work to understand Omicron.
His comments follow new statistics which show the proportion of primary school pupils in Scotland achieving the expected levels in literacy and numeracy fell during the pandemic.
Achievement of Curriculum for Excellence Levels (ACEL) data for 2020/21 also highlighted that the attainment gap between youngsters in the most and least deprived areas grew as the poorest were hit hardest.
Education Secretary Shirley-Anne Somerville said that the new data showed the stark reality the Covid-19 pandemic has had on Scotland’s young people, adding that before it hit the year-on-year trend in the ACEL data was positive.
On Tuesday, First Minister Nicola Sturgeon announced new guidance for Scots in a bid to slow down the spread of the highly transmissible Omicron variant.
She asked people to limit their socialising to just three households and if possible avoid crowded events and venues.
Businesses and hospitality premises will also face new legal requirements to enforce social distancing and reduce crowding, in what some labelled “another terrible blow” during the festive period.
Prof Leitch described the new guidance as “horrible” and said that he was “gutted” when the new variant arrived just in time for Christmas.