The government's plan for students due to complete their Higher School Certificate was unveiled on Friday, with those outside the worst affected areas in Sydney able to re-enter the classroom on August 16.

"It won't be normal classes but, certainly, it will be a level of presence to ensure that no students are disadvantaged in terms of acquiring their qualifications," Premier Gladys Berejiklian said on Friday.

Activities include "essential curriculum delivery, wellbeing support and check-ins".

Preparations for drama and oral exams will be permitted, with the onus on schools to develop plans to ensure social distancing between on-site students and to "leverage their physical spaces", Education Minister Sarah Mitchell said.

The story is different for 24,000 year 12 students living or learning in the eight, higher-risk local government areas of Blacktown, Campbelltown, Canterbury-Bankstown, Cumberland, Fairfield, Georges River, Liverpool and Parramatta.

They have no date of return to the classroom and their chance to sit final exams rested with "a golden opportunity" to get vaccinated next week at an Olympic Park stadium, Health Minister Brad Hazzard said.

He compared students to Australia's Olympians given priority vaccine access before flying to Tokyo, urging students to "go for gold".

The eight council areas - home to two million people - have recorded five in every six cases in Sydney in the past fortnight.

Students will receive emails with booking details over the weekend while a hotline (1800 922 886) will try to answer parents' questions.

The premier asked students to treat everyone they encounter at the vaccine hub as a potentially positive case.

"You may not have seen your friend for a couple of months, but don't abandon social distancing," Ms Berejiklian said.

Delaying the return to school until vaccinations had time to take effect and moving all trial exams online were among measures the state's two main teachers unions were calling for on Thursday.

NSW Teachers Federation President Angelo Gavrielatos said teachers and principals were breathing easier.

"Sanity has prevailed."

The union was prepared to consult with government about returning students to classes from August 28, should it be safe to do so, he said.

"The announcement (to return all Year 12 students to classes by August 16) should never have been made - it was premature and defied health advice, common sense and science," Mr Gavrielatos told AAP.

The opposition raised concern that year 12s in the worst-hit areas would be disadvantaged.

"We do not want a two-tiered HSC - we think the government needs to take this back to the drawing board," NSW Labor leader Chris Minns said.

Mr Minns also called for the release of health advice that states "40,000 kids and teachers crisscrossing Sydney" was consistent with the government's plan to have nearly zero transmission by August 28.

Australian Associated Press