COVID-19 case have spiked dramatically in NSW, with 30,402 new infections recorded, but authorities say it's due to a data glitch.
NSW Health says about 10,000 positive rapid antigen tests registered between Sunday and Monday are included in figures released on Wednesday, due to a data processing problem.
"These positive RATs from Sunday and Monday artificially inflate the cases being reported today for the 24 hours to 4pm Tuesday," NSW Health said.
It comes a day after NSW reported 10,689 cases, up by more than 1700 from the previous day.
Five people died on Tuesday and 1016 people are in hospital, with 36 in intensive care and 15 on ventilation.
Three men and two women are among the latest fatalities.
One person was in their 30s, one in their 60s, one in their 70s and two in their 80s.
NSW is just four deaths away from recording 2000 fatalities for the entire pandemic.
Health authorities are warning NSW to brace for a new wave of the virus, with cases likely to double by the middle of next month.
Health Minister Brad Hazzard said the same researchers who correctly predicted the Omicron summer surge have forecast another wave of cases that will peak next month.
Acting Chief Health Officer Marianne Gale said within weeks the new Omicron sub-variant BA2 will be "by far the dominant strain in NSW".
Former Australian Medical Association boss Tony Bartone is also warning about a winter surge of cases, saying BA2 and the cold season posed a new threat as people spent more time indoors together.
"The BA2 'son of Omicron' variant seems to be much more easily spread in family situations. Especially when children are largely unvaccinated," he told the Nine Network.
He urged parents to get their children vaccinated and eligible Australians to get a booster shot.
"We saw in January how quickly things can change," Mr Bartone said.
"Be wary, be vigilant. Don't forget the lessons of the past."