Senior doctors have urged the government to halve the current twelve-week wait between doses of the Pfizer/BioNTech Covid-19 vaccine. 

In an statement released on Saturday morning the British Medical Association (BMA) said it had written to England’s chief medical officer Professor Chris Whitty.

According to the BBC, the letter describes the current rollout plan for the jab as “difficult to justify”. 

When the vaccine was first announced health officials said there would be a three-week gap between the first and second doses of the vaccine, in line with clinical trials. 

But this has now been extended by the government to twelve weeks, in a push to get as many people vaccinated with their first dose in as short a time as possible. 

Speaking at a Downing Street press briefing on Friday, Whitty said the change in approach was a “public health decision”, which would allow “many more people to be vaccinated much more quickly”.

The government’s Joint Committee on Vaccination and Immunisation (JCVI) has said that the Oxford-AstraZeneca vaccine is thought to be effective with a 12-week delay between doses. 

But both Pfizer and BioNTech have warned they have no evidence their vaccine would continue to be protective if the second dose is given more than 21 days after the first.

The BMA said it supports giving a second dose up to 42 days after the first dose, but that a longer gap is not in line with World Health Organisation (WHO) guidance.

It therefore urged Whitty to “urgently review the UK’s current position of second doses after 12 weeks”.

“The UK’s strategy has become increasingly isolated from many other countries,” the BMA said.

“BMA members are also concerned that, given the unpredictability of supplies, there may not be any guarantees that second doses of the Pfizer vaccine will be available in 12 weeks’ time.”

The Department of Health and Social Care (DHSC) said in an emailed statement that its priority was to protect as many people as possible as quickly as possible.

“The decision…to change vaccine dosage intervals followed a thorough review of the data and was in line with the recommendations of the UK’s four chief medical officers,” a DHSC spokeswoman said.

Some 5.38 million people have been given a first dose of vaccine in the UK, according to government figures.