And it could means universities and schools see an extended spell of remote learning, according to National Clinical Director Professor Jason Leitch.
All of mainland Scotland will go into Level 4 restrictions for a three-week period from Boxing Day to counter rising cases of the virus, the First Minister announced at the weekend.
Professor Leitch warned MSPs on Holyrood's Covid-19 committee today that if the new variant sees the R (reproductive) number rise by up to 0.9, as some forecasts indicate, an enforced period of strict lockdown may have to be imposed.
"That would mean everyone working from home who possibly could - it would be back to March rather than November," he warned.
Leisure centres, gyms and places of worship would all face closure.
Professor Leitch added: "It also takes you into a conversation about education which will have to include those in universities and colleges.
"That work is ongoing. Preparations for a variety of versions of university and college are already in train. They already have a staggered return ready, they have blended learning ready.
"They don't have blended learning for everybody, but if they had to they would revert to that and we would only bring the practical courses back like dentistry or motor mechanics, whatever has to be back.
"Schools have to be in that equation. We will have to keep that under review. We have bought ourselves a little bit of time with the staggered return and that will help us, but paying attention from a public health perspective to the vulnerable children and those of key workers which we will have to have in some kind of establishment that is safe and looks after their wellbeing. All those things have to be on the table."
Nationalist MSP Willie Coffey told the committee that the major concerns he hears from constituents about Covid-19 is the lack of adherence to restrictions in supermarkets and other shops.
Constitution Secretary Michael Russell said the authorities need to be made aware of any evidence of supermarkets failing to enforce the "strictest set" of enforcement rules.
"We need to know and others need to know," he said.
"Councils need to know for environmental health enforcement - there needs to be a recognition that we have to, as a society, as a community, say collectively that is not good enough. We need to do this properly and to help each other to observe it.
"We should not be censorious to each other if we can avoid it.
He added: "Let's start of by saying to to people, explaining to people why we feel uncomfortable, what we need to do, why we need that to change and to try to encourage people to change."
He added: "If there is persistent offending, if there is lax-ness and carelessness which is deliberate then that has to stopped."