A March-style lockdown rather than the restrictions used in November may be needed to suppress the new strain of coronavirus, Scotland’s national clinical director has said.
Jason Leitch said it will be “very, very difficult” to keep the R number below one given how transmissible the variant is.
Mainland Scotland will be placed into Level 4 of restrictions on Boxing Day, with the islands moving to Level 3.
Ministers are currently considering if stricter rules are needed in Level 4 areas in light of the mutated strain emerging.
Prof Leitch gave evidence to the Scottish Parliament’s Covid-19 Committee on Wednesday morning.
The UK-wide New and Emerging Respiratory Virus Threats Group (Nervtag) found the new strain has a growth rate about 71% higher than the existing Covid-19 virus, he said.
Referring to Nervtag’s conclusions, Prof Leitch told the MSPs: “Probably the most important point in their minutes is unfortunately this one.
“It was noted that the code numbered variant has demonstrated exponential growth during a period when national lockdown measures were in place.
“So that suggests that the November lockdown in the south east of England wasn’t sufficient to drive down the R number for this variant.”
While scientists are still trying to understand the new variant fully, he said the R number could be increased by 0.4 to 0.9 compared to the existing virus.
Discussing what further measures could be needed, Prof Leitch said: “If it got to a point where we needed more and if the R number increases by even 0.4, which is the lower end of the suggestion from Nervtag, that means – in old money – you have to get to an R number of 0.5.
“And this new variant would take you to 0.9 compared to the old variant.
“That is really, really difficult. So that would mean everybody working from home who possibly could.
“It would be back to March rather than November.”
He said there would be implications for places of leisure such as gyms as well as the education system.