But chief medical officials said it was better to vaccinate more people with the first injection.
The Pfizer-BioNTech vaccine was the first approved injection in the UK, with 9,44,539 people receiving their first injection.
The first person to receive the injection on December 8, Margaret Keenan, has already received a second injection.
Pfizer has stated that it has proven the effectiveness of the vaccine only when the two vaccines have been given up to 21 days apart.
However, chief medical officers said that most of the “initial protection” came from the first injection.
“A second dose of vaccine is likely to be very important for the duration of protection, and sometimes an appropriate dose may increase the effectiveness of a vaccine,” they said.
“In the short term, the further increase in vaccine efficacy from the second dose appears to be moderate; most of the initial protection from clinical infection is after the first dose of the vaccine.”
The decision to delay the second dose has clearly raised concerns.
Some evidence regulators say – at least for the Oxford vaccine – it will boost immunity.
But for those who are about to receive a second dose soon, there is no doubt that it will be a pity that they will have to wait now.
But the move is about practicality. The UK is in the midst of a public health crisis and despite millions of pre-prescribed doses, there are concerns that vaccine supply will not be as smooth as everyone would like.
There is a global demand for these vaccines and there must be times when supply does not meet demand.
So the logic of the move is that by spreading this thin resource more widely, it will get the most benefit – not just for vulnerable people but for everyone.
Life was put forward and a livelihood was lost.
This is the fastest way back to normal.
Even if it leaves some of the vaccine susceptible to disease, it should theoretically at least protect them from serious illness.
Given that we are now, the argument is that that is a price worth paying.