Covid: Herd immunity cannot be reached unless children over 12 given vaccine, experts say

Experts criticise ‘unnecessary delay’ in expanding roll-out after decision to offer 16 and 17-year-olds jab

The Covid-19 vaccination roll-out must be further extended to children aged 12 and over to achieve herd immunity in the UK and suppress the virus, scientists have warned.

The country’s 16 and 17-year-olds will be offered their first dose of Pfizer vaccine within weeks after the Joint Committee on Vaccination and Immunisation (JCVI) advised they should be included in the roll-out.

But leading experts have warned that it will not be possible control transmission of the coronavirus through herd immunity unless the roll-out is expanded to include 12 to 15-year-olds.

Herd immunity – the point at which the spread of the disease is controlled after enough people become immune – requires around 85 per cent of a population to be protected through vaccines or antibodies, according to epidemiologists.

“It’s not going to be possible to get herd immunity without vaccinating younger children,” Dr Deepti Gurdasani, epidemiologist at Queen Mary University London, told The Independent.

She criticised the “unnecessary delay” in rolling the vaccine out to all teenagers – and pointed out that many 16 and 17-year-olds would not get the jab before returning to school at the start of next month.

“We could have had all of this age group [16 and 17-year-olds] vaccinated before September. And because we are not expanding [to over-12s] schools will remain places where children get infected and pass it on. So we need to do more and expand to a wider age group.”

Republic of Ireland’s health authorities announced on Thursday that children aged 12 to 15 can register to get the Covid vaccine from next week. France, Canada and the US have already started vaccinating those from 12 years upwards.

Urging the UK to follow suit, Dr Gurdasani added: “Even if we do vaccinate more children, it will be quite hard to achieve herd immunity. We don’t know quite how much immunity we will get when the variants keep evolving. But we certainly won’t have any chance if we don’t vaccinate children.”

Dr Stephen Griffin, associate virology professor at Leeds University, said the JCVI had failed to make clear why they had changed the advice for 16 and 17-year-olds, but not for children of a younger age.

“We can’t get to herd immunity by doing this [vaccinating 16 and 17-year-olds] alone,” said Dr Griffin. “We need to get further along the road of vaccination to break more transmission chains.”

He added: “We’ve never achieved herd immunity purely through natural immunity for any infectious disease, so I don’t see why you would start now. If you don’t have a vaccination programme that comprehensively covers children and young people, you’re never going reach that’s sort of threshold.”

It comes as the roll-out for children was labelled “frankly shambolic” by the head of one of the country’s leading medical colleges – who said doctors were still “in the dark” over the details.

On Thursday the JCVI announced that 16 to 17-year-olds – around 1.4 million people – will offered a first dose of the Pfizer vaccine without parental consent within weeks. But it is not year clear when they will be offered a second dose.

It follows a recommendation two weeks ago that those children over 12 at increased risk of illness from Covid because of underlying conditions are offered the Pfizer vaccine.

Dr Camilla Kingdon, president of the Royal College of Paediatrics and Child Health, said the planning for the roll-out was not good enough. She said England’s national vaccine booking system was still not accepting bookings for anyone under the age of 18.

“Our members are constantly being asked questions by young people or their parents for which they don’t have the answers because the systems aren’t in place and the detailed advice has not been provided,” she said.

The Scottish government said the roll-out of the Pfizer vaccine to 16 and 17-year-olds will begin as soon as Friday, and is expected to be complete by the end of September.

Beyond the practical difficulties ahead, Professor Lawrence Young, vice president of Warwick Medical School, said that all children 12 would eventually need to be included in the roll-out for the UK to get a “wall of immunity”.

He told The Independent: “The statements from the JCVI yesterday suggested they were considering it – so why don’t we just go for it? It would be morally wrong not to and let the virus rip through our young people. Why would we do that?”

Prof Young pointed out that current Covid vaccines do not give long-lasting, “sterilising” immunity offered by jabs for the measles and other diseases. But widening the roll-out remained important to suppress transmission, the Warwick expert argued.

He added: “I think it’s about protecting the well-being of children, as well as making sure schools aren’t having to shut down, or send home large numbers because of infection. The safety data is there [for over-12s]. It’s important we get on with expanding the roll-out. I suspect in time we will.”

Professor Jonathan Van-Tam, England’s deputy chief medical officer, said there was “no time to waste” and that he expects the roll-out for 16 and 17-year-olds to start in a “short number of weeks”, which will coincide with the reopening of schools after the summer break.

The deputy chief medical officer hinted the roll-out could be extended to 12 to 15-year-olds at some stage in future. “My sense is that it is more likely, rather than less likely, that the list will broaden over time, as more data becomes available,” he said.