America's top infectious disease expert has apologised after suggesting the UK had "rushed" the vaccine approval process.

Dr Anthony Fauci told CBS American regulators would do a “more thorough job” – although he later backed away from the comments, saying he was not implying sloppiness on the part of British authorities, in whom he had “great faith”.

The MHRA said it had carefully assessed all the data on the vaccine and no “standards of safety, quality and effectiveness have been bypassed”.

And on Thursday Dr Fauci also told CBS News that Britain “kind of ran around the corner of the marathon and joined it in the last mile” adding: “They really rushed through that approval.”

But in a later interview with BBC News, he said he did not mean to “imply any sloppiness”, adding: “I do have great faith in both the scientific community and the regulatory community at the UK.”

Now the UK’s medicines regulator has defended itself against criticism from America’s top infectious disease expert, saying it has “rigorously assessed the data” for the Pfizer/BioNtech Covid-19 vaccine.

The Medicines and Healthcare products Regulatory Agency (MHRA) commented after Dr Anthony Fauci, the director of the US National Institute of Allergy and Infectious Diseases, warned the speed at which the UK approved the Pfizer/BioNTech vaccine could undermine confidence in the jab.

Joint Committee on Vaccination and Immunisation (JCVI), which advises ministers, has said care home residents and staff should be prioritised for the jab, followed by those aged 80 and above and frontline health workers, then younger age groups and the clinically vulnerable.

The Pfizer vaccine is difficult to get to care homes because it must be kept at around minus 70C and is initially packed in large batches.

Pfizer and BioNTech have said the jab can be sent to care homes, as long as the vaccine travels for no more than six hours after it leaves cold storage and is then put in a normal fridge at 2C to 8C.

Officials in Scotland said they would move to vaccinate elderly residents from December 14 with the Pfizer jab after talks concluded batches of the jab could be split into smaller packs.

Elsewhere, Facebook has vowed to start removing false claims about new coronavirus vaccines, including misinformation that vaccines contain microchips.