With Covid rates rising across the country - and one reason behind this potentially being waning immunity for people who've previously had a vaccine - a roll-out of a fourth jab has long been considered inevitable.
Health Secretary Sajid Javid announced that the Joint Committee on Vaccination and Immunisation had recommended the roll out of a "spring booster" to certain groups on February 21 - which was also the day the Government revealed its Living With Covid strategy.
Now, it's understood that preparations for the beginning of a fourth jab campaign are well under way.
Read more: Newcastle City Council 'steps down' Covid alert level, but will remain 'vigilant and prepared'
And here ChronicleLive answers the questions you may have about the next vaccines.
Who will be first in line for dose number four?
Sajid Javid has confirmed that initially, the fourth jab will be offered to the most vulnerable groups. He told ITV's Peston programme it was only right to follow the JCVI advice.
"They look at the data very, very carefully and their latest advice as you say is that there should be a second boost – or let’s call it a fourth dose – but to focus on those over 75, those in care homes, those who are immunosuppressed," he said.
The Health Secretary added these jabs would begin to be administered "by the end of the month" and that we were "completely on track for that".
When will other people be offered the next jab?
However, at this stage there is no firm timescale for when the wider population will get their next jab. Mr Javid continued by saying that at this stage the JCVI had recommended this happen later in 2022.
"I think at some point they will and they’ve actually been clear," he said. "And their most recent advice is that they think that towards the end of this year, maybe in the autumn, there will be a need to give a lot more people a boost, an offer of a boost, but I’ll wait for that advice."
The JCVI said that the extra jabs were necessary because although vaccines offer strong protection, their effectiveness does wane over time and Covid surges are expected in winter.
Why are only the most vulnerable getting it first?
Groups identified as "most vulnerable" are in need of another dose for several reasons. One being that they will have been among the first to receive their booster jabs.
It is also the case that in many of those who are, for example, immunosuppressed even the booster jab had limited effectiveness in producing an immune response.
Speaking to the British Medical Journal, Michelle Willicombe, a consultant transplant nephrologist at Imperial College Healthcare NHS Trust, London, said data from a study by researchers at Imperial College London and from the US and France, showed that "around half" of patients for whom two doses of vaccine hadn't been enough to stimulate their immune system did respond to a booster.
But she added that that still left "around a quarter" of immunosuppressed patients still had no responses after three doses.
Will we need a fifth jab after that?
It's likely to be the case. Many medical experts have long suggested that regular boosters may become a necessity - akin to the yearly flu jab. In December, Dr Stewart Findlay, who is clinical director for the North East's vaccine programme, said: "It looks likely that we will be giving people booster doses annually or even twice a year - and we need to get more staff into primary care to make sure that this can be done without impacting too much on the day-to-day work that our community pharmacists and our GPs need to do."
Ministers have previously discussed how Covid vaccinations may become an annual occurrence, in January Mr Javid said we "may well" need annual vaccines.
