The South African strain of the coronavirus is unlikely to become dominant in the UK over the coming months, the deputy chief medical officer for England has said .

Professor Jonathan Van-Tam said that unlike the strain which emerged last year in Kent, the South African mutation did not enjoy a “transmissibility advantage” over other variants.

Speaking at a No 10 news briefing, he said he believed it was “likely” that the existing vaccines would be effective in preventing serious illness in people who became infected with the new South African strain.

But he suggested that people in high risk groups may need booster jabs – either annually or biennially – as the vaccines were updated to cope with new mutations of the virus.

His comments came after South Africa suspended use of the Oxford/AstraZeneca vaccine after a small trial among young adults found that there was a reduced level of protection against infection and mild disease.

But Prof Van-Tam said the findings should not be a cause for concern in the UK where – unlike South Africa – the Kent variant was now the dominant strain.

“Early data … does not suggest the South African variant has a distinct transmissibility advantage over our current virus,” he said.

“Because of that there is no reason to think that the South African variant will catch up or overtake our current virus in the next few months.

“Our immediate threat is from our current virus and there is now plenty of evidence that the vaccines that we are deploying are effective against our current virus.”

He said a number of vaccine manufacturers – including Pfizer – had released data suggesting they still had a “substantial effect” in reducing serious illness from the South African variant and he believed the same was likely to be the case for the AstraZeneca version.

This is not a big fright, it is not a big surprise

If the South African variant did become more prevalent in the UK, he said people in high risk groups could be given an updated vaccine – with only a single shot likely to be required.

“You can be re-vaccinated and we are taking a lot of steps behind the scenes to ensure that we can be in that position,” he said.

“Just as variations to the virus were inevitable, it ‘s almost inevitable that we would at some point need variations to the vaccine. This is not a big fright, it is not a big surprise.”