The Health Secretary has confirmed preparations are under way to offer Covid booster jabs in the UK from next month, but a leading vaccine expert has suggested they are not needed.

Sajid Javid said the Government is awaiting advice from the Joint Committee on Vaccination and Immunisation (JCVI) but indicated that the plan is likely to be for over-50s to be offered a booster Covid-19 vaccine at the same time as a flu jab.

He said those who got their jabs when the vaccine rollout began in December last year will be prioritised.

Speaking during a visit to a hospital in Milton Keynes on Tuesday, he said: “When it comes to booster jabs we are waiting for the final advice from JCVI, that’s our group of independent clinical advisers, and when we get that advice we will be able to start the booster programme, but I anticipate it will begin in early September, so I’m already making plans for that.”

He said the vaccine programme has created a “wall of defence”.

He said: “It’s massively reduced hospitalisations, deaths from Covid are mercifully low and that’s because of our vaccination programme.”

The Department of Health said three quarters of adults in the UK have now received both doses of a Covid-19 vaccine, something hailed by Boris Johnson as a “huge national achievement”.

A total of 86,780,455 doses have been administered in the UK, with 47,091,889 people receiving a first dose (89%) and 39,688,566 people receiving both doses (75%), the department said.

But Professor Sir Andrew Pollard, who played a key role in developing the Oxford/AstraZeneca vaccine, said any waning of protection provided by the vaccines would be “gradual” and would be picked up on quickly through UK surveillance systems, adding that “there isn’t any reason at this moment to panic”.

Asked about the potential autumn booster campaign, ahead of Mr Javid’s comments, Sir Andrew told the All Party Parliamentary Group on coronavirus: “The decision to boost or not should be scientifically driven.”

He said data suggests that the vaccines are holding out against the virus which causes Covid-19 and protecting the double-jabbed from severe disease and death.

He said it is not the case that we “get to the end of September and suddenly find that the pandemic starts again”, and added that if there is a “fall-off in protection” it would happen gradually and “at a point where we can pick it up and be able to respond”.

And Sir Andrew warned that rolling out booster doses while other parts of the world still have none does not look good.

He told a session of the group of parliamentarians: “The optics of going for a major booster programme in the UK is a really difficult one.

“Both what we’re talking about in terms of what would be a moral failure with no doses in many parts of the world and three doses here.

“So there’s that aspect.

“But there’s also the messaging, because that says to other countries ‘well if the UK needs three doses, we need three doses’.

“And so that has a huge implication for sucking even more doses out of the system.”

Health officials have previously set out a timeline for a potential booster campaign, saying all over 50s and the clinically vulnerable could be offered a third dose as well as a flu shot between September and the middle of December.

Dr Gregg Gonsalves, associate professor of epidemiology at Yale University, told the session that countries should prioritise vulnerable people in other parts of the world before considering booster programmes.

He said: “Every country in the world that is sitting on doses needs to get them on a plane and get them to the places that need them now.

“You have vaccinated most people in the UK.

“If we’re going to boost people in the UK and United States before the rest of the world, we have to ask really what we’re doing and whom we’re doing it for.”

Dr Ayoade Alakija, co-chair of the Africa vaccine delivery alliance for Covid-19 and Nigeria’s former chief humanitarian coordinator, said, while there is “awe and respect” for the work of scientists in the UK and institutions like the NHS, there has been “significant reputational damage” on a political and diplomatic level when it comes to vaccine equity.

She called on the UK to engage more with world leaders, telling the parliamentary session: “Perhaps that is where leadership could be shown in this moment, perhaps there is a moment for the honourable Prime Minister to still have his Churchillian day, to call the G7 and to engage with the leaders of the low and middle-income countries of the world.”