The Joint Committee on Vaccination and Immunisation has decided that the Covid jab roll-out will continue based on age.
After all over-50s have been offered a first dose those aged from 40 to 49 will be invited for a vaccine.
Then those aged over 30 will be vaccinated, followed by those aged over 18.
There had been calls to prioritise frontline workers such as teachers and police officers.
Professor Wei Shen Lim, Covid-19 chair for JCVI, said opting to keep with an age-based priority system for phase two of the vaccine programme meant it would be simpler to administer.
He told a Downing Street press briefing: “Operationally, we know that age is a very easy and simple way to structure a vaccine programme.
“When we consider occupational groups, there are occupations where the risk of exposure to the virus might be higher.
“If we look at who is at risk of severe disease, ie. being hospitalised or sadly dying from Covid-19, even within occupational groups, it is those people who are older who are more at risk compared to younger individuals.
“In the instance of phase two, it is the people who are aged 40-49 who are at higher risk compared to younger individuals.”
Professor Wei said the JCVI believed it would be quicker to administer vaccines on an age-based priority in phase two.
He told a press briefing: “Speed is important.
“Of all the different approaches to vaccination, getting vaccines into arms as quickly as possible is the fastest way and the best way to maximise benefit to the population.
“Taking all of these factors into account, we advise that the offer of a vaccination in phase two should still be age-based, starting with the oldest and proceeding in the following order: those aged 40-49, followed by those aged 30-39 and lastly those aged 18-29.
“Following an age-based programme will be simple and simplicity has been one of the cornerstones of the current programme in terms of speed and its success.”
Dr Mary Ramsay, head of immunisations at Public Health England (PHE), said there were signs that the rates of deaths and hospital admissions in the vaccinated age groups were declining.
Speaking at a press conference on Friday, she said there was now evidence the Pfizer-BioNTech vaccine reduces the risk of systematic infection in older people three weeks after their jab and there was an even higher protection against more severe forms of the disease.
She added: “We are beginning to see signs that the rate of deaths and the rate of hospitalisations in those vaccinated age groups are declining at a faster rate than in younger populations.
“So, again, really showing that phase one approach with giving vaccines to as many people in those age groups as possible as quickly as possible has really had an impact.
“We are ready to think about what we are going to do in phase two of this programme.”