People on the coronavirus vaccine priority list will be invited to take up leftover doses at the end of each day at “very short notice”, HuffPost UK can reveal.

Community chemists will roll out the scheme to use up every last drop of the Pfizer/BioNTech vaccine, which cannot be kept at room temperature for long, to ensure wastage is kept to an absolute minimum.

It means patients will be informed that they have minutes to attend a local pharmacy to get an unplanned end-of-day jab – but is unlikely to mean a repeat of scenes in the US, with queues of hopeful patients outside vaccine hubs, because the leftover appointments will be still be allocated through a booking system.

It has come about because of a “patient group direction” (PGD) issued this month by NHS England advising pharmacists that an additional dose of the Pfizer/BioNTech vaccine can be taken from each vial – which officially only contains five shots, but includes enough provision for wastage to create a sixth if users are careful.

Similar guidelines have already been given to GPs.

High street pharmacies began delivering the vaccine last week through online booking systems – which explicitly warn people against attending too early in order to maintain social distancing.

It is currently being offered to people aged 80 or over, people aged 70 or over, and people who are otherwise clinically high risk – in that order.

Bristol pharmacist Ade Williams hopes to begin delivering the vaccine next week, and told HuffPost UK: “I do know there is an overarching principle which is that no vaccine dose should be wasted – it’s very important.

“If we are in a position where we have vaccine doses left to use up, you may be contacted. Wastage, in the context of where we are, would be tragic.”

In England, initial bookings are managed through a centralised system, with left-over doses being coordinated locally. 

Williams stresses: “If you have 10 extra doses or missed doses, you are not going to be chasing those 10 people yourself. It will be joined up working, it will not just be left to clinicians to pick their own patients. It will be an amalgamated list of priority patients that is agreed across the system. I know the local lists will reflect the national priorities as well. 

“If the dose is already drawn and you need somebody in 10 minutes, you could think: ‘What about my patient who is 80 and lives across the road?’ Then you would notify the central system and they would do the calling. 

“These are the kind of scenarios the guidance takes in. It’s still in the spirit of the priority list, but you can’t just call your friends and neighbours. Some people will be given very short notice, that is going to happen. The fundamental thing is that we can’t just book anyone. Every dose that is administered is visible and you have to explain why you contacted that person.” 

Similar programmes are underway abroad, with some vaccination hubs in Israel offering the vaccine to walk-ins outside the high-risk cohort at the end of the day to avoid thawed doses going to waste.

Though management of how these leftover doses will have to be carefully managed in order to avoid situations such as one in Buffalo, New York, which saw “hundreds if not thousands” of people congregating in search of the jabs.

Guidance from NHS England states: “Each vial contains at least five doses. It is normal for a small amount of liquid to remain in the vial after withdrawing the final dose. When low dead volume syringes and/or needles are used, the amount remaining in the vial after five doses have been extracted may be sufficient for an additional sixth dose. Care should be taken to ensure a full 0.3ml will be administered. Where a full 0.3ml dose cannot be extracted the contents should be discarded. Any unused vaccine should be discarded six hours after dilution.”

The Department of Health and Social Care has issued similar advice on administration of a sixth dose of the Pfizer vaccine, which must be stored at ultra low temperatures and cannot be safely kept once it has been thawed. 

A working assumption of 5% wastage has been factored into vaccine delivery plans – which is what is usually used for the flu vaccine, and what the World Health Organisation (WHO) says is the rough global average.

Royal Pharmaceutical Society (RPS) chief scientist Gino Martini said: “In line with guidance from NHS England, those delivering Covid-19 vaccines are able to administer an extra dose of the Pfizer/BioNTech vaccine if obtainable from the vaccine vial.

“We fully support pharmacists being able to administer these extra doses to patients to help reduce waste and to support the efficient implementation of the vaccination programme.”

A National Pharmaceutical Association spokesperson said: “In order to maximise uptake of the vaccine and minimise waste as well as protect the most vulnerable, local health care teams will sometimes need to be agile in their approach. However, everyone is clear about the importance of protecting those most at risk.”