Queensland has reported 42 new cases of COVID-19 in the past 24 hours - up from 31 on Saturday - in a clear sign that the more infectious Omicron strain is spreading through Queensland, Chief Health Officer John Gerrard said on Sunday.
Dr Gerrard said Omicron was now the dominant COVID strain in Queensland, accounting for 21 of the past 25 cases tested.
"This is happening very rapidly, even more rapidly than we thought," he said. "We thought that might take weeks."
However, Dr Gerrard said almost all of the recent cases were mild, which showed that the vaccines were successful in preventing serious infections.
"Most of the patients we have seen who had the Omicron strain and have been vaccinated had very mild symptoms," he said.
But while 42 new cases may seem like a relatively small number, he said, "this is double the number we saw just 48 hours ago".
"With a doubling rate - if this rate continues - we will see significant numbers in January as predicted."
Of the 42 COVID-19 cases reported in the past 24 hours:
Dr Gerrard said the two unlinked cases were of concern, "because they have been acquired in the community somehow".
"But we have to assume there are undetected cases in the community," he added.
Dr Gerrard said he had spoken with most of the doctors dealing with the recent COVID-19 cases and had been told the patients' symptoms were mild.
"All of the patients, with the exception of one, have minimal symptoms or no symptoms," he said.
"The one patient who is moderately unwell - they are breathless in one of our teaching hospitals - was unvaccinated.
"It is disappointing at this stage of the pandemic - a once-in-100-year pandemic, when every Queenslander has had the opportunity to get vaccinated - that we are still seeing unvaccinated patients being admitted to hospital with significant symptoms.
"We wish this lady well, and hopefully she will improve soon."
No patients were in intensive care, Dr Gerrard said, but Queensland's hospitals were preparing beds to deal with the expected increase in cases.
"You will be aware that previously, we have been admitting all patients with COVID-19 to hospital, mostly for infection-control purposes," he said.
"We are moving away from that model, and we are clearing beds to allow for capacity in the coming weeks."