LONDON, Feb. 24 (Xinhua) -- COVID-19 and the Omicron variant "will never be a flu in the same way that we acknowledge flu," a British medical expert has said, as British Prime Minister Boris Johnson announced the end of COVID-19 restrictions in England and the start of "living with COVID-19."

"To call Omicron just another version of flu is a gross understatement," David Strain, who has signed so many death certificates related to the novel coronavirus since the start of the pandemic, told Xinhua in a recent interview.

"It is a different system of the body that's being attacked. It's using different pathways, and has a significant vascular effect that the flu doesn't have," said Strain, also a senior clinical lecturer at the University of Exeter Medical School.

On Monday, the British prime minister announced his plans to end self-isolation rules and the provision of free coronavirus tests in England, one day after British Queen Elizabeth II tested positive for COVID-19.

"To compare the Omicron variant with flu or any other viral illness is just not right," said Strain.

According to the country's Office for National Statistics, around 1.3 million people in Britain, accounting for 2 percent of the total population, were experiencing "self-reported long COVID", whose symptoms persist for more than four weeks after the first suspected coronavirus infection.

"If new mutations do arise, the big worry is it will be too late to do anything about it before we even know (what) is going on. There are still many uncertainties in the whole area of (the novel) coronavirus," said Strain.

"If you're in a crowded indoor space, or if you are in a position where you can't adequately ventilate, keep that mask on. Just because you don't have to doesn't mean that you shouldn't have a mask on," he said.

"We are still in a position today in Britain where we have multiple hospital wards, even in small centers, that are full of COVID patients," said Strain. "The last two years have been incredibly trying. We've got used to very late finishes, very early starts. We're working with staffing shortages because we came into the pandemic without enough staff, and then throughout it."

"When you hear people saying that COVID-19 doesn't exist or it's just a conspiracy to try and keep people under control, it actually makes me angry," Strain said, adding that he once signed more COVID-19 death certificates for patients in a week than what he had done in his first three years as a consultant.

"Is it the end game? We all hope that this is the end game," he said. However, "what we hope doesn't mean that's what the reality is."

"I think we're too early to say we're at the end," Strain said. ■