Brazil registered a new record number of daily Covid-19 cases of more than 137,000, according to figures supplied by the nation's Health Ministry on Tuesday.
The South American country of 213 million people is one of the worst affected in the world by the pandemic.
Its more than 620,000 deaths from the virus is second only to the United States.
Cases have been soaring in Brazil since the beginning of the year due to the arrival of the highly contagious Omicron variant and the festivities around Christmas and the New Year.
The average daily new cases at the end of 2021 was only around 8,000.
The previous high from June 2021 was more than 115,000 cases within a 24-hour period.
"The peak should be reached in February when the situation should once again stabilise," epidemiologist Ethel Maciel from the Espirito Santo Federal University told AFP.
There are concerns that the rising cases could impact on carnival celebrations at the end of February.
Street carnival celebrations in major cities São Paulo, Rio de Janeiro and Salvador have already been scrapped over concerns.
Both Rio and São Paulo still hope to maintain the colourful parades at their "Sambadrome" outdoor venues as those stadiums allow for tighter virus-control protocols than the open streets.
"The public health services are already under a lot of pressure and the next two weeks will be decisive to see what impact the infections from the New Year celebrations will have on hospital admissions," said Maciel.
She does not expect the Omicron wave to prove as deadly as previous variants, though.
Close to 70 percent of Brazilians are fully vaccinated and the immunisation of children as young as five started this week, despite objections from President Jair Bolsonaro.