A decision on whether the over-50s will need a third Covid-19 jab is to be set out by vaccination experts in the next few weeks.

If the programme is given the green light, it is expected that all those over the age of 50 or clinically vulnerable in England will be offered a booster jab before Christmas.

NHS officials have set plans in motion to deliver a joint coronavirus and flu jab campaign in the autumn, but it is still not known whether a booster jab will be needed.

Experts advising the Government – the Joint Committee on Vaccination and Immunisation (JCVI) – will deliver guidance before the programme is due to commence on September 6.

Pharmacies will play a significant role role in the programme for delivering third jabs to help top up immunity levels as GP surgeries resume usual duties as much as possible.

The Telegraph said vaccines minister Nadhim Zahawi has briefed MPs on the plans, which include the aim of delivering an average of almost 2.5 million third doses a week and carving out an increased role for pharmacies.

A Department of Health spokeswoman said: “The Government is preparing for a booster programme and JCVI (Joint Committee on Vaccination and Immunisation) have published interim advice on who to prioritise for a possible third vaccine from September 2021.

“The booster programme – which would ensure millions of people most vulnerable to Covid-19 will have the protection they have from first and second doses maintained ahead of the winter and against new variants – will be informed by the JCVI’s final advice.”

The department said more details will be announced in “due course”, with ministers understood to be waiting for further results from the Cov-Boost trial to see which vaccines should be used in the autumn programme.

Thorrun Govind, chairwoman of the Royal Pharmaceutical Society in England, said: “Pharmacists across the NHS have played a critical role in leading the successful implementation of the Covid-19 vaccination programme.

“We’d like to see widespread involvement of community pharmacy in delivering the Covid booster jab and flu jab together, depending on JCVI recommendations.

“Pharmacy has a strong track record of delivery of vaccination programmes, with over 2.7 million flu vaccinations provided last season, and with more than 600 sites delivering Covid-19 vaccinations currently.”

Dr Gary Howsam, vice chair of the Royal College of General Practitioners, said: “GPs and our teams have worked incredibly hard to protect as many patients as possible from Covid-19. The vaccination is our route out of this pandemic, and the majority of the programme has been delivered in primary care.

“General practice has a long track record of delivering vaccination campaigns, and patients, particularly our most vulnerable patients, trust GPs and our teams to get the job done.

“Alongside our pharmacy and other colleagues across the NHS, general practice will retain a key role in the programme. Due to the intense workforce and workload pressures already facing our services, not every practice will be able to get involved in the booster campaign, as they will be focused on other essential care.

“We want to see efforts to ensure high numbers of trained non-clinical vaccinators (are) available to work within general practice, supervised by a smaller number of primary care clinicians, to help to deliver this in the autumn.”

Commenting on the prospect of a booster campaign, Lis Wallace, head of UK advocacy at The ONE Campaign, said: “The real battle to beat Covid and prevent dangerous new variants is now taking place in countries where millions of people are facing deadly new waves of the virus with far less protection, so it’s alarming that the Government is choosing to prioritise booster shots.

“With falling infection rates and a successful vaccination programme that means that almost three quarters of British adults are protected, it’s vital that the Government sees the bigger picture.

“The only guaranteed way to reduce the risk of new variants undermining the progress that has been made is to get vaccines around the world as soon as possible. If we want to end this pandemic at home and abroad, then now is the time to ensure we beat this virus everywhere.”

NHS England said in July that health systems should prepare to deliver booster doses of Covid-19 vaccines between September 6 and December 17 as “quickly and safely as possible”.

In a letter to senior health leaders, the NHS said results from a number of clinical trials are expected over the summer so plans will need to “flex as new information becomes available”.

In June, the JCVI published new interim guidance setting out the priority list for who should get a third jab if a booster programme is needed.

Around 32 million people would be eligible under the plans, including over 50s, health and care workers, clinically extremely vulnerable people, and those aged 16 to 49 who are usually offered a free NHS flu jab, as well as people who are in regular contact with someone who is immunocompromised.

Professor Adam Finn, a member of the JCVI, told BBC Radio 4’s PM that any booster programme is “provisional” at the moment.

He said: “What we are doing at the moment is watching extremely carefully as the evidence comes in during the current wave to see whether there are people – and one would be particularly concerned about the people who got the vaccine earliest, that’s healthcare workers and the very elderly – in whom it looks like the protection they’ve got may be waning away to some extent.

“If that starts to be clearer that will move us towards advising that a booster programme should take place, but it is still provisional at this point.”