Covid travel: UK signs deal for 35m more Pfizer/BioNTech vaccine doses - BBC News
The new deal will help to "future-proof" the UK's vaccination programme, the health secretary says
So we know that another 35m Pfizer-BioNTech vaccines are on order, on top of the 100m that have already been used or are on the way already - but who are they earmarked for?

Because Prizer was the first vaccine to become available for use in the UK, that is what was given to the elderly and most vulnerable who were prioritised when the vaccine rollout started last December.

Oxford-AstraZeneca was the second to be approved and because it was quickly available in particularly large numbers, it became the predominant vaccine as the UK rollout started to work down the age groups.

But when rare instances of blood clots in younger people were linked to the AstraZeneca jab, under-30s were told they wouild be offered Pfizer or Moderna vaccines rather than the AstraZeneca one. Since then the AstraZeneca vaccine has been largely used for the second vaccines of those people who were given that first time around.

The UK regulator has now approved the use of the Pfizer-BioNTech vaccine in children aged 12-15 and the UK's vaccines committee will now decide whether children should get the jab.

The UK's booster programme is due to start next month but no decision has been announced on whether this third jab must match someone's first or second jab. If that is what is decided, then Pfizer will be used to boost the immunity of the elderly and vulnerable groups who were first to receive it at the end of 2020 and start of this year.