The First Minister said the Scottish Government was “considering all the ways we can get to as many people as possible” amid warnings that teacher shortages could result in pupils being sent home from school if Covid cases continue to rise.
The warnings were issued as Scotland recorded four Covid-19 deaths and 6,835 new cases in the 24 hours to Friday – a record daily high for positive tests north of the border.
More than a third of Covid cases are now in the under 19 age bracket, with schools seeing a rise in cases since pupils returned earlier this month.
Already two out of every 100 pupils are absent from school for a Covid-related reason and test positivity in the two to 17 age group has increased to 19.9 per cent this week, compared to 18.5 per cent the previous week.
A total of 14,914 pupils were absent on Tuesday due to Covid.
The soaring figures come as a study published in The Lancet showed the Delta variant doubles the risk of Covid-19 hospitalisation compared to the Alpha variant.
The study analysed more than 40,000 Covid cases in England over a two-month period earlier this year and has confirmed results from preliminary research carried out in Scotland.
Ms Sturgeon said she wanted the Joint Committee on Vaccination and Immunisation (JCVI) to decide “quickly” on when vaccinations for 12-15-year-olds could begin.
Scotland’s national clinical director Professor Jason Leitch said health services were “ready to go” as soon as they had the green light.
Ms Sturgeon stressed the importance of a decision being made on whether to vaccinate more secondary school pupils, although she said teenagers aged 16 and 17 were already being given the Pfizer vaccine, in line with JCVI advice.
"I really hope that the JCVI feel that the evidence allows them very, very soon to recommend vaccination for all 12 to 17-year-olds," she said.
Ms Sturgeon said "ideally" a decision on this would have been taken in time to allow secondary school pupils to get vaccinated before going back to school after summer.
UK Government ministers are separately putting in place contingency plans for children aged between 12 and 15 to receive a vaccination at school in England as early as September as they await the same JCVI decision.
NHS England is recruiting and training extra staff to give the vaccine to teenagers at special sites in school grounds.
Ms Sturgeon said: "Scottish schools go back earlier than elsewhere in the UK and I would have ideally liked that to have been the case before our schools go back, but the sooner we get to that point where the JCVI feels the evidence allows them to make that recommendation, I hope they do that quickly.”
"There are many countries across the world that are already vaccinating 12 to 17-year-olds. Clearly there are expert groups there who think this is safe to do.
"I suppose if I was making a plea to the JCVI, it is not for me to tell them what decision to reach, they have got to do that on the basis of the evidence, but please make it quickly.
"Because I would really like, assuming we get advice saying it is safe to do, I would really like to get on with vaccinating 12 to 17-year-olds as quickly as we possibly can."
Prof Leitch added: "We are ready for when that advice comes, the vaccination programme is ready to go."
Asked if that would mean vaccinations delivered in schools, the First Minister did not rule it out, saying that consideration was being given to the “ways in which we can get to as many people as possible.”
Seamus Searson, general secretary of the Scottish Secondary Teachers Association, had earlier said while vaccinations were vital, mitigations such as face masks should be in place for longer.
He warned about a potential shortage of teachers being off school as a result of coronavirus.
The Scottish Government has said the face mask requirement will be in place for “at least six weeks” of the new term.
“Teachers are going to contract Covid and they therefore will be missing and that is going to be a problem because children will be sent home because the teacher is not there,” Mr Searson told BBC Radio Scotland.
“That’s why I think the mitigations are probably going to go on for some time, because if the numbers keep rising I think the government has got no choice, but to go beyond the six weeks they first talked about and actually put the mitigations in place for a good deal longer.”
Ms Sturgeon said: “What we’ve got to do right now is operate in a way that tried to limit transmission. The key message is if we all behave in line with the advice given we have a chance of reducing infections.
“On the issue of face coverings we think it’s right, though I know how horrible it is for young people and we don't want it to be a requirement for longer than necessary, but right now we think it’s essential.
“We said six weeks, but if we continue to see transmission at fairly high levels that’s a mitigation we have to keep in place.”
Prof Leitch added: “Don't just follow the law, because the law has now restricted itself to only a few things, but look to follow the best things you can for your environment, whether you're the head teacher, the teacher, the parent, or the kid. So try to get yourself and your institution as safe as it can be.
"Staggered entry and exit times for kids is not the law any more, but if that makes sense for your school, in your context, with your limited access, then that's what you should do. We're not telling you every single step you have to do to keep it as safe as you can.”
The Educational Institute for Scotland (EIS) also raised concerns about the rise in cases, urging the need for continuing caution and effective mitigations to limit its spread through school communities.
General secretary Larry Flanagan said: “Clearly these figures will be a cause for concern for school communities – parents, pupils, teachers and staff. They underline the need to remain on guard to ensure schools remain Covid conscious and that mitigations are maintained.
“The EIS believes the change in contact tracing arrangements for schools is creating confusion for parents, pupils and staff. We wish to see all pupils identified as close contacts being required to get a clear PCR test before returning to class.
“This removes the ten-day self-isolation requirement, but offers a quick reassurance to school communities and will reduce the risk of in-school transmission. We also support the Scottish Government position of wishing to see all secondary pupils offered the possibility of vaccination, which will help minimise disruption to education.”
Scottish Labour leader Anas Sarwar said the surge in cases had been “avoidable” and alleged Scotland was unprepared if cases continue to worsen.
“Now is the time for ministers to begin a door-to-door scheme to ensure that the vaccine is being taken up,” he said. “And there is still a need for consistency in communicating how and why certain decisions are being made.
“But what is now more important than ever is we must have a Test and Protect scheme fit for purpose or risk losing our hard won progress.”
Conservative Covid recovery spokesman Murdo Fraser said: “The Scottish Fiscal Commission are reporting that Scotland’s economy is on course to rebound strongly, earlier than anticipated, with the condition that we keep moving forward past Covid restrictions.
“The SNP Government need to put recovery as the priority over clinging onto powers which, at this stage, are not justified.”
Asked about the booster vaccination plan for older and more vulnerable people, which is due to begin in September, the First Minister said they were again waiting on JCVI advice.
“We’re expecting it any day, and similar to my plea earlier I hope it’s sooner rather than later, but we are preparing for it and have all the arrangements in place to get going with that,” she said.
"The interim advice from the JCVI gave us the order of priority for booster jags and that’s the basis on which we’re planning.”
Prof Leitch added: “They just haven’t fired the starting pistol. They told us to get ready, but they needed to look globally at countries that vaccinated fast including us, Israel, Chile and a number of others to decide when is the sweet spot for injection number three.
"That's the exam question they’re answering and haven't quite yet but my understanding is they will imminently.”