THE whole of the UK should follow Scotland's model of using a "harsh lockdown" to try and push the coronavirus to the lowest level possible, the chair of global public health at Edinburgh University has said.

Professor Devi Sridhar said Scotland had imposed tough measures despite having a lower infection rate than England, Wales and Northern Ireland.

She told Sky News's Sophy Ridge On Sunday programme: "If we look at Scotland, Scotland was already running a lower infection rate but to go into quite a harsh lockdown over the holiday period, to extend the school holidays, to really try to get those numbers low, I think, I would hope the rest of the UK would follow that model, which is we have got to really crunch this.

"We have got to eliminate as much as possible to the lowest level of this virus because that is how we will reopen our economy."

She added that this was the lesson from East Asia, Pacific countries and Norway and Finland which have kept numbers low through public health guidance and measures.

First Minister Nicola Sturgeon announced severe lockdown restrictions for Scotland on Saturday.

Indoor mixing will only be allowed on Christmas Day and most of Scotland will be put into the highest level of lockdown from Boxing Day, with a "strict travel ban" preventing travel to other parts of the UK.

Sridhar also said it is too early to tell how severe the effect of the new strain of coronavirus will be.

She said there are three pieces of information scientists are looking for.

READ MORE: Scottish mainland to move to Level 4 restrictions from 26 December

"The first is, is it more infectious - is its doubling time faster - and it seems like it is, and this is what is really concerning, because it is going to become harder to suppress it with our exiting tier systems," she said.

"The second is, are health outcomes more severe - do we see more hospitalisations - and we just don't know that yet.

"And the third is, could it evade our vaccines if it actually changes quite significantly and so we don't know that either. It seems like the vaccines are still effective.

"But this just also shows why supersession is important. The more virus that is circulating the more chances there are to have different mutations as well as jumps into different animals, across species and back into humans and then it is harder for us to keep a handle on the situation."

She said schools should be kept open as much as possible during the pandemic but a distinction should be made between younger children who are unlikely to spread the virus and older pupils.

"I think we need to divide kids under 12 which we know generally have not transmitted that well between each other - we haven't seen many outbreaks in nurseries and primary schools - and secondary schools where children are very much like adults after age 12 and how we manage those," she said.

"But schools need to be kept open as much as possible and the way to do that is to keep our community prevalence low so viruses never even enter the school in the first place."

She added that low level restrictions over a long period of time are "not going to work with this virus" and that a broader strategy is needed.