Tens of thousands of volunteers have been forced to put their summer holidays on hold after the NHS’s computer system refused to recognise their Covid vaccination trial jabs.

As many as 40,000 volunteers have been told by the Deputy Chief Medical Officer that the NHS’s system will not accept proof that they have taken part in a clinical trial for several more weeks.

That has left many unwilling to risk booking a holiday – even if they have had two jabs – because a green tick will not yet have appeared on their vaccine passport.

NHS officials have refused to guarantee a date by which this will be done, leaving many hopeful travellers frustrated.

One volunteer who took part in the trial of the Johnson & Johnson vaccine at Barts Hospital, in central London, told The Telegraph: "I was just trying to do the right thing in helping to trial a vaccine at a time when the drugs were experimental and I was putting my own health at risk for the good of others. 

‘Kick in the teeth’

"But it feels like a kick in the teeth that the thanks that I get is not being able to go on holiday because the NHS computer says no. Surely it would not have been impossible in the six months since I had my second jab for someone to simply enter my details onto a separate IT system?”

The volunteer added: “I am sure that thousands of other volunteers feel like me that their much needed holidays are on hold. 

"Although the NHS has promised that it will be sorted by the end of this month, I cannot even book a trip abroad until I can see a green tick on my vaccine passport as officials have not guaranteed a date by which it will be fixed, and I would risk wasting thousands of pounds on a holiday I can’t go on – even though I have had two doses of the Johnson and Johnson single shot vaccine and have been double jabbed since February.”

Officials at Barts NHS have confirmed that the information has not yet been entered onto NHS systems, which means that volunteers can only get a letter of vaccine confirmation for internal events, such as sporting occasions, and not international travel.

Volunteers have pointed out that some countries, including France, have only been letting people with vaccine passports in for months, putting them at a significant disadvantage.

Whitehall officials say the problem cannot be fixed for a few more weeks.

Travel countries on the red, green and amber list

In a letter to vaccine volunteers, Professor Jonathan Van-Tam, the country’s Deputy Chief Medical Officer, said: “The Department of Health and Social Care makes a firm commitment to all volunteers in formally approved Covid-19 vaccine trials in the UK that you will not be disadvantaged in terms of any future domestic vaccine certification, if introduced, compared to anyone else who has had their vaccines under the standard NHS programme.”

He added: “The government will ensure that information on those in clinical vaccine trials is linked to any potential mechanisms to demonstrate your vaccine status to ensure that anyone on a vaccine clinical trial can prove they are in a clinical trial and therefore should be treated as fully vaccinated. Operationally, it will take a few weeks for the NHS to complete the programming work, but it will happen before the end of July.

“Participants in well-regulated clinical trials should also not be disadvantaged as global travel resumes. We believe the added risk of allowing the relatively small number of clinical trial participants to travel (in the UK approximately 40,000 people, the vast majority of whom have been vaccinated) is strongly outweighed by the benefit of ensuring that recruitment and retention into clinical trials can continue.”

A DHSC spokesperson said: "The NHS Covid Pass service is helping tens of thousands of English and Welsh citizens demonstrate their vaccination status quickly, easily and for free, both for international travel and for use at events as part of the Events Research Programme.

"The information displayed is from national NHS systems and if a patient’s information is incorrect or missing they can contact their GP who will be able to update their record.

"The NHS Covid Pass service will in the coming weeks display vaccine information for people enrolled in clinical trials."