European nations face another alarming COVID spike because they eased pandemic rules too soon, a senior World Health Organisation official says.

Coronavirus is spreading rapidly again in 18 European countries, including Britain, France, Italy and Germany, Hans Kluge, WHO’s regional director for the continent, said.

COVID is also on the rise across Australia against as the BA.2 subvariant of Omicron spreads rapidly.

NSW had another 24,803 cases and eight deaths on Thursday. Among those to die was a two-month-old Newcastle baby, who had no underlying conditions.

There were another 10,259 infections in Victoria, along with 11 deaths.

Queensland reported 11,018 cases and six deaths. South Australia had 4742 more infections and two deaths – with the Australian Education Union calling for an early end to term one due to continued high absences and infections among teachers and other staff in schools.

Cases are expected to climb as high as 30,000 in NSW and 20,000 in Victoria in coming weeks as BA.2 spreads.

The worrying rise comes amid fears of a looming winter spike. It is expected to be combined this year with the flu, which has been largely absent in Australia since the start of the pandemic.

The Australian Technical Advisory Group on Immunisation was expected to give formal advice to Health Minister Greg Hunt on Thursday about a potential fourth jab for up to five million Australians ahead of the forecast winter surge.

The fourth dose would likely be for Australians over 65, as well as for immunocompromised individuals.

Mr Hunt said the government would follow the health advice.

“I’m expecting to get the advice over the course of [Thursday] and will consider it and have more to say probably in the next 48 hours,” he said.

However, Mr Hunt said he was confident the country’s health system would be able to withstand any additional surges of cases.

“We’re now, on yesterday’s numbers, at 26 Australians who are on ventilation. We have a 7500-person capacity, and with COVID, there are 26,” he said.

“Vaccinations, the treatments that are available, the capacity of our hospital systems, all of those things have come together, and that’s one of the elements which has contributed to one of the lowest rates of loss of life in the world.”

Also this week, the nation’s chief health officers and state officials discussed isolation rules at an Australian Health Protection Principal Committee meeting. The Victorian and NSW governments have been working on a plan to ease rules for household contacts, but the Nine Newspapers report it has been pushed back amid the growing caseload.

On Wednesday, Dr Kluge blamed sudden changes in COVID policies in many European nations for the surging infection numbers. They had lifted measures “brutally, from too much to too few”, he said.

Many European countries reimposed tight restrictions on social gatherings as the Omicron variant emerged late last year. Those measures were drastically scaled back in recent weeks when data showed that the strand was less severe than earlier COVID variants.

On Thursday, the Netherlands became the latest European nation to drop just about all COVID measures.

With BA.2 spurring a new round of infections in Europe, Dr Kluge said he remained “optimistic, but vigilant” about the state of the pandemic in the continent.

BA.2 is also leading to another leap in infections in the US as it rapidly becomes the dominant source of COVID cases there. The US Centres for Disease Control and Prevention estimated this week that 35 per cent of new coronavirus cases were due to the subvariant.

Restrictions are also being lifted across the US. CNN reports that there are no US states that have mask mandates any longer – although some do still require masks in some settings.

Researchers in Britain and Denmark have found that BA.2 has similar hospitalisation rates to the original Omicron strain, which is already lower than the previous Delta variant.

Dr Leana Wen, an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health, said most people did not need to worry.

“It’s likely that the US will see an increase in COVID-19 cases in the coming weeks, as this is the pattern we’ve seen before,” Dr Wen said.

“Our government officials should prepare for what could be coming and increase the availability of tests and treatments, and continue to urge people to get vaccines and boosters. But I don’t think this is something that the general public should be overly concerned about at this time.”