Millions scrambled to get an earlier second dose of coronavirus vaccine on Wednesday as over-40s took advantage of new rules on the timing of the jab, while some under-40s found they were also able to change their appointment.
The government has slashed the time gap between doses from 12 weeks to eight in a bid to accelerate the vaccine rollout.
But some under-40s have said they were able to cancel existing appointments for their second jab and sign up for another one several weeks earlier than originally planned, despite not being eligible.
It is not immediately clear if the discrepancy is due to a technical error.
NHS Digital, which runs the online booking system for Covid vaccines, has appealed for users not to rebook their appointments unless invited.
One 25-year-old told The Independent they were initially offered a second dose appointment 11 weeks after their first dose.
They cancelled this and have booked one two weeks earlier, and closer to their home.
Others have taken to social media to share how they managed to push their second doses earlier.
One user said he was “under 32” and moved his gap between doses from 11 weeks to over eight weeks.
Another Twitter user said he was under 40 years old and had moved his second dose on Tuesday so it was three weeks earlier.
Others who managed to rebook for a time closer to their first dose tried to spread the word on Twitter.
“If you’ve recently had the Moderna jab, worth cancelling and rebooking your 2nd dose,” one user, who said he was 29 years old, said. “I just did and am now getting my 2nd dose 15 days earlier than originally planned.”
People replied to say they had managed to move their own vaccine forward by cancelling their existing appointment and rebooking.
Someone else tweeted on Monday evening that they were in their 30s and managed to move their appointment for their second Pfizer dose nearly four weeks earlier.
One reply said they had moved their appointment from mid-August to July and were in their 20s.
Boris Johnson said on Monday that the government would “accelerate” second jabs for over-40s by reducing the dosing interval from 12 weeks to eight weeks “so they get maximum protection as fast as possible”.
There have been no changes over second doses for under-40s.
An NHS spokesperson said: “On advice of the JCVI, the NHS is contacting people aged 40 and over to bring forward their second vaccination.”
They added: “No one needs to contact the NHS – you only have to rebook your second dose if you’re invited to do so.”