Children have to be vaccinated to reach herd immunity against Covid, Israeli health director says

Children may have to be vaccinated against Covid to achieve herd immunity, a top expert claimed today. 

Britain has yet to start offering youngsters jabs, with No10’s top scientific advisers wanting better safety data before recommending ministers on whether they should press ahead with the controversial move. 

Children are already being vaccinated in Israel and the US, with over-12s in both nations able to get Pfizer’s jab.

The countries are aiming to squash the disease through inoculating youngsters, with the hope of eventually achieving herd immunity. 

Dr Asher Salmon, deputy director general of Israel’s health ministry, said ‘nobody knows’ the exact threshold for herd immunity. But when asked on BBC Radio 4’s Today programme if it was impossible to reach without inoculating children, he said: ‘We believe so.’  

Dr Salmon said: ‘When vaccinating children, there are two purposes. The first is of course to protect the individual child.

‘The second issue, of course, is to create an effective herd immunity in our society. 

‘If we would leave around 20 to 30 per cent of our population unvaccinated, we would always have a risk of an explosion of cases. 

‘It may start in kids with no major hospitalisation effect but at another point it would also touch other groups including high risk groups and the elderly population.’  

Children may have to be vaccinated against Covid to achieve herd immunity, Dr Asher Salmon, deputy director general of Israel’s health ministry, claimed today. Pictured: A girl receives a Pfizer vaccine in Rishon LeZion, Israel, on June 6

Herd immunity is the point at which a virus can no longer spread effectively through a population because enough people are protected against it, either through jabs or getting infected.

Since the start of the pandemic there has been a massive debate over just how many people require immunity to fully suppress the spread of Covid.

Early figures suggested the threshold could be in the region of 70 per cent of the population.

America’s top infectious disease expert, Dr Anthony Fauci, has also claimed the true figure could be in the region of 90 per cent. 

Dr Salmon said: ‘Nobody really knows what the exact line regarding herd immunity and Covid. We don’t even know if we can use the term herd immunity. 


Herd immunity is the indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous infection.

Effectively, it means that once people have some form of immunity, it reduces the ability of a disease to spread among the population.

Therefore, someone who has antibodies either through previous infection or vaccines, acts as a ‘barrier’ to the virus.

If you have enough ‘barriers’ then the disease cannot effectively spread through a population.

But in the case of a new virus, such as with Covid, the virus can spread essentially without any barriers — which can lead to a pandemic.

The World Health Organisation says it supports achieving herd immunity through vaccination, not by allowing a disease to spread through any segment of the population.

But one expert told MailOnline that Covid is here to stay and that the key is reaching a ‘herd immunity threshold’.

This keeps the virus at what is known as an endemic level — where a disease is regularly found among the population but is not harmful enough to impact on society.

Keeping Covid within the herd immunity threshold, which can vary particularly in winter when diseases such as flu and coronavirus spread quickly, will mean it is kept at a ‘manageable level’, the expert added.

Research shows the current crop of Covid vaccines help by increasing the antibody response to the virus — therefore heavily reducing the risk that someone can be made seriously ill.

But data is not yet available about how effective the vaccinations are at preventing transmission.

‘But from an effective level, it seems we need to vaccinate 70 per cent to reach this elusive line and to do so we need our kids to be vaccinated.’

However, Israel has a much higher proportion of children than the UK — more than 30 per cent compared to 21 per cent. 

For Britain to vaccinate 70 per cent of the population, it would require 46.6million people are jabbed.

Currently only 42million people have had a first dose, with the roll-out in England yet to open up to adults between 18 and 20.

The figures would suggest that it would be possible to hit the same threshold as Israel without vaccinating children.

The Medicines and Healthcare products Regulatory Agency (MHRA), which polices the safety of drugs in the UK, has already approved Pfizer’s Covid jab for 12- to 15-year-olds. 

But ministers have yet to expand the roll-out to children, despite Whitehall sources talking of plans to dish out jabs to youngsters in September.

No10 is waiting for guidance from the JCVI, or Joint Committee on Vaccination and Immunisation, which advises them on the inoculation drive.

Yesterday, it was revealed the panel — made up of some of the country’s top vaccinologists — wants to wait for more data on how safe vaccines are for children, amid concerns about heart damage.

Pfizer and Moderna’s vaccines have both been linked to extremely rare cases of myocarditis — inflammation of the heart — particularly in young men.

There are fears the condition could also affect children after vaccination, who face a low risk of dying from Covid.

Discussing the issue today, Dr Salmon admitted officials ‘don’t know anything about the issue’ in children.

Israel’s vaccine roll-out to 12- to 16-year-olds only began two weeks ago and is going ‘quite slowly’, so data for how many cases occur in youngsters is scarce.  

Dr Salmon suggested Israel could begin vaccinating children younger than 12 by the end of the year once the results of clinical trials in the age group come back. 

Pfizer, Moderna and Johnson & Johnson have all begun large-scale trials to test their vaccines’ safety an efficacy on children younger than 12, with results expected this autumn. 

Scientists are divided on whether children need to be vaccinated in the UK, with some insisting it will be necessary to counter the more transmissible Indian ‘Delta’ variant. 

Professor David Livermore, a microbiologist at the University of East Anglia, told MailOnline moving the roll-out on to children posed a moral dilemma, with legitimate safety concerns meaning it is not worth risking children’s well-being for the sake of adults. 

One of the Government’s senior scientific advisers also warned of the ethical dilemma posed by vaccinating children — who face a one-in-a-million risk of dying from coronavirus.

SAGE’s Professor Calum Semple, an expert in outbreak medicine at the University of Liverpool, said he is against vaccinating the 14million children in the UK.

The MHRA said it is ‘closely monitoring reports of myocarditis and pericarditis received with the Covid vaccines’. 

It has recorded just 34 cases of myocarditis after Pfizer jabs — a similar number to after the AstraZeneca vaccine — and only two after Moderna, but says numbers ‘similar or below expected background levels’.

Meanwhile, US health chiefs have announced officials will gather tomorrow to discuss 226 plausible cases of heart inflammation in under-30s given the jabs in America. 

Centers for Disease Control and Prevention (CDC) bosses yesterday admitted the number of cases was higher than expected and that most were in boys and young men. However, they insisted the complication was still rare. 

All the cases met the CDC’s ‘working case definition’ of myocarditis and pericarditis but the actual number of reports made stands at almost 800. Hundreds of affected patients are still being reviewed.

Among the cases spotted in the US, three are in intensive care, 15 are hospitalised and 41 have ongoing symptoms. 

The CDC continues to urge everyone aged 12 and older in the US to get vaccinated and says it is not clear if either condition is actually caused by the shots.

However, similar links were also uncovered in Israel, Canada, and the Pfizer vaccine was yesterday rejected for all children aged 12 to 17 in Germany who do not have underlying health conditions.