On Wednesday, British Prime Minister Boris Johnson cautioned that the vast majority of COVID-19 patients who ended up in critical care had not got their booster vaccination, urging others to obtain their shots.

On a visit to a vaccination clinic, Johnson claimed some physicians told him that up to 90% of COVID-19 patients in intensive care had not got their booster doses.

“It pains me to say this, but the vast majority of individuals who are now ending up in critical care in our hospitals are not enhanced,” he added. “I’ve spoken with doctors who indicate that the number of persons in intensive care is approaching 90%.”

Britain is currently reporting record COVID infections, with 129,471 registered on Tuesday, driven by the highly transmissible Omicron variant of the virus. There have also been anecdotal reports of people struggling to get tests.

While daily hospitalization figures have increased, they are still well below the crisis endured by hospitals earlier this year, with about 1,000 people currently being admitted daily compared to 4,000 in January.

“The Omicron variant continues to cause real problems, you’re seeing cases rising in hospitals, but it is obviously milder than the Delta variant,” Johnson said.

He added that people should celebrate New Year’s Eve cautiously after he decided not to bring in tougher restrictions in England to limit the spread of the virus.

“I think everybody should enjoy new year but in a cautious and sensible way. Take a test, (think about) ventilation, think about others but above all, get a booster,” he said.