Changes to Covid self-isolation rules in Scotland have been announced, which could have a big impact on staffing in schools.

The self-isolation rule will be cut from 10 to seven days at midnight, if people are negative on lateral flow tests for the previous two days and have no fever, first minister Nicola Sturgeon told the Scottish Parliament this afternoon.

Meanwhile, the requirements of close contacts who are under 18 years and four months - in other words, of school age - have also changed.

Here are the key points for schools from today’s Covid statement:

• First change to self-isolation applies to those who test positive for Covid: “initial advice” is still to self-isolate for 10 days, but there is now an option to end isolation after seven days as long as you have no fever and record two negative lateral flow tests.

• Second change to self-isolation applies to close contacts of positive cases, including household contacts who are either under the age of 18 years and four months or who are older than that and fully vaccinated (that is, with first, second and booster or third doses): the requirement to self-isolate will end and be replaced by a requirement to take a lateral flow test every day for seven days.

• Any close contact over 18 years and four months and not fully vaccinated will still be asked to self-isolate for 10 days and take a PCR test.

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Ms Sturgeon also reiterated a previous message about pupils and testing: “All secondary school children are being asked to take a lateral flow test on the night before or morning of their first day back, and thereafter to test twice a week and also in advance of mixing socially with people from other households.”

She added that “staff in all educational and early years settings should take a lateral flow test just before starting back to work”.

Ms Sturgeon, who said that “I know the next few weeks will be challenging for pupils, staff and parents”, also highlighted that those aged 12-15 can now go to drop-in centres for their second vaccine dose.

“I encourage everyone in that age group to do so as soon as possible,” she said.

Scottish pupils in around a third of local authorities were due to return to school from the Christmas holidays today. Some councils reported that all schools were operating as normal, but in other areas, some children are learning online.