About 4000 people - some with placards reading "Save your nurse, one day she will be the one saving you," or "My body, my choice" - took part in the march, according to police in Belgium's capital.

The noisy rally ended outside the Belgian health ministry, where police at one point used pepper spray to keep some demonstrators away.

There were no reports of injuries.

Starting January 1, health care workers in Belgium will have a three-month window in which to get vaccinated against the coronavirus.

Those who remain unvaccinated will be notified that their contracts will be suspended unless they provide a certificate proving recovery from COVID-19 or a recent negative test.

From April, those without a proper justification for refusing to comply could be dismissed.

According to some estimates, about 60,000 health workers across the country of 11.5 million people are not vaccinated against COVID-19.

"I think that everybody should have the choice," Virginie, a doctor's assistant from the southern Belgian region of Namur who did not want to provide her full name, told the Associated Press.

"If we get rid of the non-vaccinated staff, we will never be able to make it. It is already tough enough."

Belgium reported an average of 17,000 new daily cases over the last week and about 300 people were admitted to hospitals each day.

As of Monday, 816 people were in intensive care, a rise of 7 per cent over the previous seven-day period.

"It's tense and complicated," Benjamin D'Heur, a nurse from the city of Liege, said.

"There is COVID, on the one hand, with people literally between life and death. ICUs are saturated," he said.

"And there is professional exhaustion that we hear about and see more and more. People are burned out or on sick leave, and who can blame them. The government must do something about it."

Australian Associated Press