The lockdown comes as thousands of celebrating school leavers are due to arrive in Byron Bay and other parts of northern NSW over the next month from this weekend.

Ballina MP Tamara Smith posted on Facebook on Wednesday night about the situation at the Aquarius Backpackers.

“I’m closely monitoring a situation in Byron Bay this evening where a positive Covid-19 case and 84 close contacts have been identified at Aquarius Backpackers in Byron Bay,” she said.

NSW Health has locked down the hostel for seven days, impacting 84 guests.

“I’m told (they are) being supported with food, health and support,” Smith said.

NSW Police have placed a 24-hour guard on the hostel to ensure compliance.

“My thoughts are with everyone in that situation as it will be a tough time,” Smith said.

Thousands of HSC students are about to descend on the resort town for schoolies celebrations.

Some 80.9 per cent of residents in the Byron Bay local government area are fully vaccinated. Although high, the coverage rate lags the state average of 92 per cent.

Officers are due to hold a press conference on Thursday about the launch of the force’s schoolies operation in the Tweed/Byron Police District.

Police say they will be conducting a high-visibility operation for the duration of the schoolies period, targeting drug and alcohol-related crime and anti-social behaviour.

Meanwhile, unvaccinated year 12 students have been granted an exemption to attend school year 12 formals, dinners, or graduations.

Health Minister Brad Hazzard said the 2021 cohort “had an incredibly tough 18 months”.

“They deserve to be able to party with their friends and enjoy one of the biggest celebrations of their life,” he said on Thursday.

The exemption means year 12 students who have not been vaccinated for COVID-19 will be able to celebrate with their friends if they abide by the public health requirements of the venue they’re attending.

NSW has recorded 276 COVID-19 cases and no deaths overnight.  There were 74,926 tests undertaken in the 24-hours until 8pm on Wednesday.

NSW Health says there are 191 people with COVID in hospital and 31 of them are in ICU.

Some 92.1 per cent of people 16 and older are fully vaccinated while and 94.4 per cent have had one jab.

Victoria has recorded 1254 new COVID-19 cases and five deaths, with the proportion of its fully vaccinated 12-plus population officially hitting 90 per cent.

The new infections bring the number of active cases in the state to 10,276, including 310 in hospital, slightly raising the seven-day average to 309.