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Should we vaccinate under-18s?

Unlike many other countries, the UK is only vaccinating under-18s who are particularly at risk from the virus, or who live with extremely vulnerable adults. Is that the right decision?
July 30, 2021

Let no one tell you that the question of whether or not to vaccinate under-18s against Covid-19 is a no-brainer. It’s a very difficult choice, which is reflected in the diversity of informed opinion. All the same, many governments and regulators have decided in favour of jabs for those over 12, including in the US, Canada, France, Denmark, Austria, Germany, Italy, Switzerland, Singapore, China (where the Sinovac vaccine can be used for children as young as three), Spain (from late August) and very recently, Ireland. Rather few seem to be opting for the UK’s position of approving Covid vaccines only for under-18s with pre-existing conditions that put them at particular risk (such as a suppressed immune response or multiple learning disabilities), or who are living with especially vulnerable adults. Even Finland, which has this policy for 12- to 15-year-olds, is vaccinating those who are 16 and above, and Norway seems likely to adopt that same compromise.

While the 15th July decision of the UK government’s Joint Committee on Vaccination and Immunisation (JCVI) not to extend general vaccination to children and adolescents is not as exceptionalist as the government’s initial herd-immunity pandemic strategy, it does seem to be increasingly a minority position. It also contrasts with the judgment of the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) that the Pfizer-BioNTech vaccine is safe for 12- to 15-year-olds and that, in the words of Chief Executive June Raine, “the benefits of this vaccine outweigh any risk.”

Many experts are perplexed by the decision. “I’m concerned that JCVI isn’t paying attention to the US and other countries,” says Devi Sridhar of Edinburgh University. “Delta is a gamechanger.”

“It is a gamble to delay vaccinating teenagers in the UK, and one that might not pay off well,” says immunologist Brian Ferguson of Cambridge University. But opinion differs: virologist Jonathan Ball of the University of Nottingham feels that the JCVI’s decision to limit vaccination of children to vulnerable cases “finds a sensible middle ground.”

That the JCVI’s position differs from that of the MHRA need not in itself be surprising: the latter is purely a scientific assessment about safety and efficacy, while the former is a policy decision that must embrace wider considerations. However, Penny Ward, a visiting professor of pharmaceutical medicine at King’s College London, is perplexed by the contrast with some other countries, especially America. “I don’t follow why there is a positive risk benefit position for this age group in the US but a negative one in the UK,” she says, “particularly as the US has been vaccinating 12- to 15-year-olds for some time now and is therefore in a better position to have directly observed experience.”

The key dilemma is that the risks of severe illness and death from Covid-19 among under-18s are so low that they do not obviously outweigh the risks of serious side-effects from the vaccines. Concerns about the risk of blood-clotting complications from the AstraZeneca vaccine, which seems higher among younger people, do appear to counsel against its use for this age group. But there are worries that the Pfizer and Moderna vaccines, which use the newer mRNA technology, might also have harmful side-effects. Reports of the heart inflammatory conditions myocarditis and pericariditis among young men over 16 given these vaccines in Israel are particularly troubling. It’s not yet completely clear if or how these cases are linked to the vaccines, and the incidence is very low: about 67 cases per million second doses for boys aged 12-17, and just nine per million for girls. Nevertheless, the JCVI has opted for caution.

The committee also mentioned a body-wide inflammatory condition called PIMS-TS, noted in around five in every 10,000 children infected with Covid in the second wave, 1 per cent of whom died from it. This might sound like an argument in favour of vaccination—but because the vaccine stimulates the immune system (which controls inflammation), it’s possible that the risk might actually be worsened in vaccinated children who catch the virus.

What’s more, a high proportion of children experienced unpleasant side-effects in vaccine trials, such as fatigue, headaches and joint pain. These are probably passing symptoms, but we don’t know for sure—and you’d need good reasons to knowingly expose children to such ailments.

One argument for vaccinating children is that it’s not directly for their benefit but to reduce transmission of the virus in society generally. After all, given the significant level of full vaccination (68 per cent) among adults in the UK now, cases of Covid-19 are highest among young people: one in 70 secondary-school children were infected in late June. But it’s a complex ethical question whether children should be given a drug for the sake of others—in particular to protect those adults who have declined to be vaccinated themselves. It’s possible, given the low incidence of serious Covid in the largely vaccinated adult population, that huge numbers of children would need to be vaccinated to prevent just a single such case of hospitalisation in adults.

There’s another consideration: given the level of protection against severe Covid among the UK population, and the populations of many other wealthy western countries too, is it morally right to be vaccinating children, who are at very low risk anyway from the virus, rather than channelling vaccines to low-income countries where adults are still largely unprotected?

“Is it morally right to be vaccinating children rather than channelling vaccines to low-income countries where adults are still largely unprotected?”

And yet… The arguments on the other side are also strong. While children are extremely unlikely to die from Covid (only 25 people under 18 are thought to have died from the virus in England since March 2020), many experts are worried about their susceptibility to long Covid: effects of infection, such as fatigue and “brain fog,” that can go on for many months. A recent study in the Lancet showed that, among adults, there is a significant deficit in cognitive abilities, on average, among people who have had Covid. The problem is that we just don’t know how big a problem this might be for under-18s. The JCVI statement says simply that “Emerging large-scale epidemiological studies indicate that this risk is very low in children, especially in comparison with adults”—which some experts regard as a premature dismissal of a potentially serious concern.

“There are currently up to 30 children being admitted to hospital in the UK every day with severe Covid,” says Ferguson. “The impact of ‘long Covid’ in children is hard to currently quantify, but with high numbers of children now being hospitalised with the disease, many may suffer with long-term effects of this infection.”

It’s also surely true that the JCVI decision must be seen in the light of the wider context of the UK’s pandemic. It might seem more reasonable if it had been made against a backdrop of efforts to contain the spread of the virus and reduce the risk of young people becoming infected. But precisely the opposite is the case: with virtually all restrictions removed on 19th July, the government seems resigned—or even eager—to seeing the virus move through the young, unvaccinated population unchecked. Some researchers are convinced that the strategy now is to achieve “herd immunity” through a mixture of vaccination and natural infection.

There’s arguably a broader imperative to keeping infection rates low too: in a partly vaccinated population, it would reduce the danger of more vaccine-resistant variants emerging. This is a real possibility with enormous potential consequences, but one that is very hard to quantify. While one can’t readily base policy on such imponderables, the issue should be more clearly acknowledged.

And although it is hard to see how any age limit on vaccination could avoid a degree of dissonance around the threshold, it does seem odd that young people over 18 are so vigorously being encouraged to get their vaccine shots while 17-year-olds are being told it is too risky. Those who will turn 18 in the next three months are being allowed to start their vaccination programme already, but still, the contrast is jarring.

Peter English, former chair of the British Medical Association’s Public Health Medicine Committee, suspects that the JCVI’s decision, contrasting as it does with that of the MHRA, was not just a medical one but also partly political. It does not seem to have taken careful account of secondary issues such as children passing infections to adults or the risks of long Covid, he says.

“The focus on preventing deaths and admissions rather than cases is a clear steer that JCVI do not consider attaining protective levels of population immunity via vaccination to be a priority,” says professor of medicine Stephen Griffin of the University of Leeds. 

What’s more, the full implications of the JCVI’s decision have not been clearly acknowledged. Epidemiological modeler John Edmunds of the London School of Hygiene and Tropical Medicine suspects that the fall in new infections since around 15th July has been largely driven by the ending of the school term, and by the large number of children (as many as 20 per cent) isolating, or already off school post-exams, shortly before that. If so, this highlights how strongly schoolchildren are now a driver of infection. “They’ve always been important, but now they’re really important because we’ve shrunk infection down [by vaccination] to the younger age groups,” Edmunds tells me. “Things that affect children and young adults are now going to have a disproportionate effect on the epidemiology.”

So if there is to be no mass vaccination of this age group, we have to recognise that this is likely to lead to more major disruption—including more disruption of children’s schooling when it resumes in September. “I think people need to be aware that that is what will happen,” says Edmunds. “You can’t expect to leave children unvaccinated and not have a lot of disruption that results from that—to them and their education, but also to society more generally. They will seed infection out to the rest of society more generally. It’s inevitable.”

It’s possible there could be a middle way. The UK’s study of the effectiveness of the Pfizer vaccine against the Delta variant showed that a single dose already offers good protection (around 94 per cent) against hospitalisation from Covid—yet most cases of myocarditis that seem to be associated with the vaccine happen after the second dose. So it could be that a single dose would suffice for children and young people. Epidemiologist Azra Ghani of Imperial College London also says that it could be important to review the JCVI’s decision if rates of infection in the general population grow much higher.

There is another question here about medical rights. Should parents of children be denied the opportunity to decide whether they wish to offer their children protection against a disease that could be nasty both for the child and for them? Isn’t it odd that a government so keen now to devolve handling of pandemic to “personal responsibility” is withholding it in this instance? At any rate, the worry of some experts that the ruling has been made as much on political as on medical grounds reflects a general lack of trust in the basis on which such policies are being determined: a default assumption that they are (like the relaxation of mandatory mask-wearing) primarily political calculations. That is perhaps the most problematic aspect of the issue: it suggests an erosion of faith that such decisions are being made with our best interests in mind.

Update: On 4th August, the JCVI changed its recommendation as follows: “JCVI advises that all 16 to 17-year-olds should be offered a first dose of Pfizer-BNT162b2 vaccine.” The JCVI is now reviewing whether a second dose should be offered later, and expects to reach a decision on this within a period no greater than the delay between the two doses currently given to adults—so that if the decision is to provide a second dose to this age group too, that can happen on the same timescale.

The JCVI’s statement explains the considerations behind the new decision, but offers no explanation for why it differs from that announced on 19th July—what new evidence, in other words, changed the committee’s mind. Neither was any explanation given in the press briefing on 4th August at which the new position was announced. It was hardly surprising, then, that the very first question from the press—from Sanchia Berg of BBC News—was precisely this. In response, Wei Shen Lim of the JCVI mentioned that the earlier decision was influenced by the concerns about reports of myocarditis in vaccinated young people, and that more is now known about this possible complication as vaccination programs elsewhere have continued. Presumably he intended to imply that this seems now not to pose the risk it first potentially appeared to. Or perhaps the decision was influenced by a new study in the US which shows that myocarditis among young men is more likely after Covid-19 infection than after vaccination. The audience, however, was left to make its own deductions.

Already—and predictably—the JCVI’s new decision has provoked an outcry from the euphemistically “vaccine-hesitant.” This makes clear communication of the reasoning all the more vital. That the JCVI seemed to feel it could (partly) rescind a controversial recommendation two weeks later, yet offer no clear account of what new evidence has prompted the change in position, beggars belief. There are good reasons to think the current decision is the right one—although it still leaves hanging the situation for 12-15-year-olds, as well as the second dose for 16- and 17-year olds—and many experts have welcomed it. But, more than 18 months into the pandemic, it seems that lessons about the importance of transparent communication have still not been learnt.