Vaccinating just 25 care home residents against Covid-19 could save a life, MPs have heard.
The figures demonstrate some of the reasoning behind the priority list set out by experts advising the Government.
Care home residents top the list which sets out nine categories of those most at risk.
Vaccinating 250 people over the age of 80 will save one life, the Science and Technology Committee was told.
But “many thousands” of train operators would need to be vaccinated to save a life, MPs heard.
The Government aims to have the top four priority groups – including care home residents and their carers, frontline health and social care staff and all those over the age of 70 – offered their first jab by mid-February.
Professor Wei Shen Lim, chairman of the Joint Committee on Vaccination and Immunisation (JCVI), told the committee: “In terms of protecting people within a constrained vaccine supply, the estimates are that we have to vaccinate only about 250 people aged over 80 to save one life.
“For care home residents, we only need to vaccinate somewhere between 25 to 45 care home residents to save one life.
“If you were trying to vaccinate, for example, train operators, then you would have to vaccinate many thousand train operators to save a life.”
“It doesn’t mean that that’s not important, but it’s weighing up the values there. That’s a policy decision as to what value one wants to weigh up.”
It comes after GP magazine Pulse reported that family doctors are “expected” to vaccinate all care home residents in England by the end of the week, and by January 24 at the latest.
Vaccine deployment minister Nadhim Zahawi said that it was his “instinct” that frontline key workers would be next in line for the vaccine after the most at-risk were immunised but said the Government would be guided by the JCVI.
“The JCVI are best-placed to look at this in terms of looking at where do we go next.
“Now, my instinct is to say, rightly so that those who are most likely to come into contact with a viral load: teachers, shop workers policemen and women would be the highest risk of getting the virus, and therefore they’re the ones we should focus on, but I would very much be guided by the JCVI.”
Dr Mary Ramsay, head of immunisation at Public Health England, said that in order to keep services running it would be a “societal decision” on which key workers are next prioritised for a vaccine.
She told MPs: “The issue is probably not about mortality but more about the resilience of the workforce.
“That, actually, is a decision that probably is beyond the health data that we normally work with.
“I think there will be other factors that we would have to consider at that time and it’s almost a societal decision, I guess, on which occupations are the ones that we most want to protect in order to keep our society going.”
But a plea has been made by AstraZeneca to get all those involved in the vaccine development and manufacture to receive the vaccine urgently.
Mene Pangalos, executive vice president of biopharmaceuticals research and development at AstraZeneca, said: “One of the things that I’m worried about is actually maintaining a continuous supply and work on this vaccine.
“Of course, with the outbreak and the pandemic where it is – I feel it’s critical to the people that are working on this vaccine are actually immunised.
“Because if you have an outbreak at one of the centres – which we’ve had actually – or in one of the groups in Oxford (that) is working on new variants, or the people that are working on the regulatory files – everything stops.
“This is a concern that I have and so again we’re pushing to try and get our key workers that are working on the vaccine project immunised to try and prevent these outbreaks.”