select search filters
roundups & rapid reactions
before the headlines
Fiona fox's blog

expert reaction to UK’s chief medical officers recommending that healthy children aged 12 to 15 are offered one dose of the Pfizer COVID-19 vaccine

The UK’s Chief Medical Officers (CMOs) have recommended that government proceed with the vaccination of 12-15 year olds against COVID-19 with a single dose of the Pfizer vaccine.


Prof Jeremy Brown, Professor of Respiratory Infection, UCL, said:

“The JCVI came to their decision purely on medical grounds; that is, in healthy adolescents there is very little severe disease caused by COVID which means there is no strong need to use the vaccine to prevent the illness caused.  And this also has to be balanced against the small risk of heart inflammation that seems to affect maybe 10 people per million vaccines given, and seems to be generally very mild but as yet we do not know the long term consequences.

“The JCVI is only able to look at the medical benefits the vaccine could have, whereas the CMOs can also assess non-medical factors, mainly time in reducing time off school and on the overall mental well-being of children.

“The effects the COVID-19 pandemic has had on disrupting schools and generating mental strain in children is unprecedented, making it entirely appropriate for the CMOs to take these factors into account and for a different approach to vaccine decisions to be taken compared to vaccine decisions for other diseases.”


Dr Alasdair Munro, Clinical Research Fellow in Paediatric Infectious Diseases, University of Southampton, said:

“The option to have a single dose of an authorised COVID-19 vaccine will be welcomed by many families.  As outlined by the CMOs and JCVI, administration of a single dose brings the majority of the health benefits whilst avoiding the higher risk of myocarditis following the second dose, mainly for young men and older boys.  Hopefully families can be reassured that the main source of controversy around recommending vaccination for this age group is that both the risks of COVID-19 and of vaccination are low.

“It will be important to emphasise that this is not mandatory, and children/young people and their families have the right to opt in or out.  As part of this, it is important that children/young people who chose not to be vaccinated for the time being are in no way disadvantaged as a result.

“We must all take note that the primary reason for recommendation by the CMOs, and as highlighted by the RCPCH, is to minimise disruption to education.  This is by far the biggest threat to the physical and mental well being of children at present, and should be prioritised.”


Prof Paul Hunter, Professor in Medicine, UEA, said:

“The announcement that despite the advice of JCVI not to recommend immunisation to otherwise healthy 12 to 15 year olds the four CMOs of the UK have collectively decided to recommend immunisation has come as no surprise.  JCVI’s decision was clearly not to the liking of the UK’s politicians, though the CMOs’ decision has been taken independently of political influence.  The CMOs have been able to consider wider health benefits and clearly consider these to move the balance of benefit versus harm towards the benefit side of the equations.  But this was not an easy decision to make and clearly there have been strong opinions expressed on both sides of the argument.

“One issue that has not been adequately addressed is whether or not vaccinating this age group will reduce threats to children’s education.

“A recent pre-print ( has suggested that the risk of myocarditis and other adverse cardiac event in boys aged 12 to 15 may be higher than originally thought but that most of the risk follows the second dose.  This was almost certainly the logic behind the CMOs’ decision to offer just a single dose of the vaccine and thereby reduce the risk of myocarditis.  As discussed below a substantial proportion of children have already had the infection and so it is going to be important to monitor possible adverse reactions in this group as it is unclear whether first doses in a previous infected individual has the same risk profile as first doses in people not previously exposed.

“But will a single dose be sufficient to prevent school disruption?  It is still far from clear how much COVID will disrupt education this year.  Although it is still too early to be sure it is starting to look like the epidemic in the general population started to decline once schools went back.  This was most noticeable in Scotland where schools went back somewhat earlier and seems to be also playing out in England.  Of course association does not necessarily mean causation so we need to wait a while longer to see whether this decline is maintained and is also occurring in school aged children.

“The impact of a single vaccine dose in this age group will depend in large part on how many children have had the infection already.  A single injection of vaccine in someone who has not had a previous infection is not that effective at preventing infection, of the order of 33% effective.  In those who have had a prior infection a single dose will boost antibody levels and presumably protection against infection, though for how long is uncertain.  We do not know for certain how many children in the 12 to 15 year age group have already had the infection but the majority of 16 year olds already have antibody from the ONS Ab survey so presumably a large proportion of the 12 to 15 year age group even if not the majority will have already had the infection and recovered.  So how much benefit to children’s education will come for this campaign is uncertain.”


Dr Simon Clarke, Associate Professor in Cellular Microbiology at the University of Reading, said:

“The announcement that the four Chief Medical Officers have agreed that the UK will vaccinate 12-15 year olds should be welcomed, as it will provide society with an extra layer of protection against Covid-19.  Making the original decision, JCVI had focused mainly on the risk to individuals in this age group, and not the risk to wider society.  The CMOs have done the same, but have looked at a wider set of criteria that influence the welfare of this age group.

“We have seen in Scotland, where schools have been back for a month, that unvaccinated children and young people are driving up infection rates to near-record levels.  While most people who are vulnerable to serious disease from Covid-19 are now double jabbed, having a large amount of virus circulating freely among young people is dangerous, particularly when we don’t know how waning immunity levels and potential new mutations of the virus could change things for the worse.

“We should remember that vaccinating young people to protect older or more vulnerable people is already common, including with newly-developed vaccines.  A new flu vaccine is created every year, and once it is tested for safety and efficacy, as has happened with covid jabs, it is rolled out to the general population.  In the UK children get the new flu vaccine every year from age four, mainly to prevent them catching and spreading flu to older adults, who are most vulnerable to dying from flu.

“All children should be vaccinated against rubella, or German measles.  Rubella is a mild illness for children, but a serious risk to pregnant women and their unborn children.  Boys are vaccinated at secondary school against human papillomavirus, HPV, not primarily for their own benefit but to prevent the spread of the virus that causes cervical cancer in women.

“Vaccines always have side effects and risks, but the scientific evidence shows the risk to individuals and wider society of not being vaccinated is a greater risk.  Yes, there are risks of side effects from the jab for children.  But parents should remember that sadly some children have been made seriously ill, and died, after catching the coronavirus.  Not getting vaccinated can also have side effects, but we call them disease.  By cutting chains of transmission through vaccination to 12-15 year olds, we will be making it safer for more people of all ages.”


Dr Liz Whittaker, Senior Clinical Lecturer in paediatric infectious diseases and immunology, Imperial College London, said:

“11 million adolescents have received the Pfizer vaccine in the USA to date, and evidence has shown that: 

  • In adults, this vaccine decreases the risk of severe disease, hospitalisations and death.
  • In teenagers, it is tolerated and results in a strong immune response, but many experience reactions (sore arm, flu like symptoms for a couple of days).
  • It decreases the risk of infection and onward transmission of SARS-CoV-2 virus, but does not prevent it.
  • There is a rare risk of heart inflammation (myocarditis), in particular with the second dose of the Pfizer vaccine, and this is greater in adolescents than in adults.  45-60 cases/million develop myocarditis with the second dose; 1-10 cases/million with the first dose (female 1, male 10).  Although they make a rapid clinical recovery, cardiac MRI imaging shows changes to the heart muscle in some patients, and it is too soon to say whether this resolves completely.

“These risks need to be considered against the risks of a child contracting COVID, as for healthy children the risk of severe disease (including pneumonia and heart inflammation) due to infection with the virus is roughly the same as the risk of heart inflammation due to the vaccine:

  • The majority of 12-15 year olds experience asymptomatic or mild symptoms when infected with SARS-CoV-2 and for healthy 12-15 year olds, a 1 in 2 million risk of death.
  • There is a rare complication of fevers and heart inflammation secondary to infection with SARS-CoV-2 (called Paediatric inflammatory multi system syndrome (PIMS) or Multisystem inflammatory Syndrome in children (MIS-C)).  Death is rare, and by 6 months the vast majority of those affected are completely back to normal, with normal cardiac MRI scans.
  • For children with chronic health conditions, such as neurodisability, the risks of severe disease, while still very low, are higher than for healthy children.
  • Based on PHE surveillance studies, 40-70% of children and young people have already been infected with SARS-CoV-2, and will have pre-existing immunity, so are unlikely to experience complications such as severe disease and PIMS/MISC.

“These are the sorts of facts on which the JCVI based their decisions – which were to recommend the vaccine for those children and young people with chronic health conditions, where the balance of benefit outweighs the risk.  They did not recommended giving the vaccine to healthy 12-15 year olds, as at this moment, based on medical evidence, the health risks and benefits to the individual child are similar.  They suggested they will continue to review evidence as it is presented, and their decision was not final.

“The JCVI were asked a narrow question: is there a benefit when considering only the medical benefits of the vaccine.  However, they suggested that other considerations may tip the balance towards benefit for our young people.  And many paediatricians agree.  There are three such considerations which are often cited: the impact of Long COVID, the need to reduce transmissions in schools, and by far the most important: the mental health benefits of enabling children to go back to school, and empowering them to help fight the pandemic by taking the vaccine.

“The JCVI could not base the decision on Long COVID – although 2-13% of this age group report persistent symptoms 12 weeks after infection, we do not know what causes this, or whether it would be prevented by vaccination.  There is an early signal in adults to suggest that vaccination decreases the risk, this is likely related to the decreased risk of infection following vaccination.  However, to date, we do not have good enough medical evidence.  The JCVI also did not base their decision on the risk of transmission in schools, although this clearly happens.  There may be other public health interventions that can help to reduce transmission, and evidence suggests that much community transmission is led by young adults (20-40 year olds), another group with relatively low vaccine uptake.  And they did not base their decision on the mental health considerations which some paediatricians are most concerned about.  We have seen a devastating number of young people presenting with mental health conditions which may be due to a combination of factors – loss of normal structure and support systems in school, anxiety about their health and the health of their family, worries about their education, the future, the economy, bereavement due to family COVID losses, etc.  For many of these young people, having the vaccine gives them an opportunity to do something to protect their ability to go to school, to protect their family and to get ‘back to normal’.  Many paediatricians believe that these other factors, a potential protection from Long COVID, a decreased risk of transmission in schools which will keep young people in education every day, and the emotional and mental well being associated with having had a vaccine, outweigh the small risk of heart inflammation.

“It is reassuring that the JCVI based their decisions on evidence, and I agree with their decision based on the aspects they looked at, but I also consider it right in view of the bigger picture to offer the choice of vaccination to healthy young people, as the CMOs have today recommended.

“Parents and young people will ultimately make this decision together as the vaccine will not and should not be mandatory.  Under no circumstances should those young people who choose not to have the vaccine at this time be penalised or stigmatised for this choice.  It should not be a limiting factor for school access, extracurricular activities, school trips etc. It is essential that the facts are available for them to read and understand as part of that decision making process.”


Dr Michael Head, Senior Research Fellow in Global Health, University of Southampton, said:

“The MHRA have previously approved the use of the Pfizer COVID-19 vaccine in children aged 12-15 years, describing the vaccine as having a positive safety profile (  There have been millions of doses of this vaccine used in children across many countries, including the USA, Canada and much of Europe.  There has arguably only been one potential adverse event of note, that of myocarditis.  The cases of myocarditis observed in vaccinated teenagers have overwhelmingly been mild, and the condition is both clearly linked to, and much more severe in, those infected with COVID-19.

“The JCVI focus is predominantly on the benefits associated with preventing severe cases of COVID-19.  Within this remit, they have concluded there would be a marginal benefit in vaccinating most children, but the benefit was not clear enough to support their recommendation.  They have previously recommended vaccinating teenagers with existing health conditions that would make them more vulnerable to a severe COVID-19 illness.

“The JCVI provide evidence and scrutiny as one part of the overall decision-making pathway.  The Chief Medical Officer will also have presented evidence to Ministers that cover the impact of other factors, such as time off school.  In my opinion, when these are areas are also considered, it is the right decision to recommend vaccination of 12-15 year old children.”


Dr Julian Tang, Honorary Associate Professor/Clinical Virologist, Respiratory Sciences, University of Leicester, said:

“I was expecting this decision and it is in line with the school influenza vaccination programme:  In particular, the benefits of the childhood influenza vaccination programme are laid out below – also by the JCVI: (“Flu vaccination programme 2021 to 2022: For the 2021 to 2022 flu season, the flu vaccination programme that already includes all children in primary school will be expanded to additional children in secondary school so that those in years 7 to 11 will now be offered flu vaccination. This significant expansion in the programme is part of the government’s wider winter planning to reduce flu levels in the population, and therefore the potential impact on the NHS, when we are likely to see both flu and coronavirus (COVID-19) in circulation.

In 2012 the Joint Committee on Vaccination and Immunisation (JCVI), the independent expert advisory group that advises the government on their vaccination programme, recommended vaccinating children against flu as it provides individual protection to the children who receive the vaccine and reduces transmission of flu in the wider population.”)

“The benefits of vaccines will always extend to the larger society – whether or not we choose to take this into account.

“Vaccinating 12-18 year old children further reduces the susceptible host reservoir for new variants to be generated, and protects the adult contacts (including their parents, teachers and other school staff) of these children from infection, which will benefit the wider society, as well as reducing any disruption to their education.”


Prof Russell Viner, Professor of Child and Adolescent Health, UCL, said:

“Vaccinating 12-15 year olds remains a very marginal balance in medical terms, although with over 10 million teenagers vaccinated worldwide we are now much clearer about safety in this age-group.  The pandemic has wrought a great deal of harm in the lives of our children and young people, including poorer mental health and disruptions to education and socialisation.  The CMOs were able to take these broader issues into account and decided that on balance we as a society should offer vaccines to all teenagers.

“This is a good decision for young people and for broader society.  It is also a testament to strong UK decision-making, recognising the critical importance of independent scientific decision-making without fear of political influence, but also factoring in key societal issues missing from a narrow focus on medical harm and benefits.”


Statement from the Royal College of Paediatrics and Child Health (RCPCH):

“Evidence from the UK and around the world has repeatedly shown us that children are highly unlikely to become seriously ill because of infection with COVID-19.  However, since even before the first lockdown, the College has been extremely concerned about the indirect effects of the virus on children and young people, primarily because of many of the infection control measures in place.

“The most important consequences of these have been the disruption to school attendance and children’s extra-curricular activities and the effect of this on their mental health and wellbeing.  It has also reduced their access to health services delivered in school and the role schools play in wider health issues such as child protection.  Reduced access to school has disproportionately impacted children from more deprived socio-economic groups and could have lifelong repercussions.

“We are aware of the many hours of intense scrutiny the Joint Committee on Vaccination and Immunisation has given to the issue of assessing the health benefits and risks of healthy 12-15 year olds being offered the vaccine.  The Committee’s view was that the margin of benefit, based primarily on a health perspective was, at this time, considered to be too small to support a universal programme of vaccination of otherwise healthy children in this age group.

“The RCPCH was subsequently asked by the UK’s Chief Medical Officers to consider the wider aspects of this issue, including that of access to school.

“We believe that vaccination could benefit healthy children, irrespective of any direct health benefit, in enabling them to have less interruption to school attendance, to allow them to mix more freely with their friends, to give more protection to friends and family members whose health may be at risk from the virus, and to help reduce the anxiety some children feel about COVID-19.  But vaccination of 12-15 year olds must be part of a concerted overall plan to ensure consistent and uninterrupted access to school.

“Participation in activities inside and outside of school are key to children’s development, resilience, and mental health and wellbeing.  We need to ensure that such participation returns to normal as a matter of urgency.  Vaccination of this age group against COVID-19 is not a silver bullet and, in isolation, will not improve school attendance.  Children who are vaccinated will have less risk of contracting the virus and less risk of passing it on to others, but they may still test positive and could still become ill, although illness is highly unlikely to be serious.

“Routine testing of children without symptoms is still interrupting children and teenagers’ school attendance and we do not believe this should continue.  Instead, schoolchildren should be tested only if they have symptoms of COVID-19.  At the same time, and as with other infections, they should not go to school if they are unwell.

“It is extremely important that any COVID-19 vaccination programme in schools does not interfere in any way with other school vaccination programmes where the health benefits are more clear-cut and have the potential to be lifesaving.

“If COVID-19 vaccinations are to be offered to this age group, children, teenagers and their families or carers must receive clear and non-judgemental advice about the risks as well as the benefits.  The decision should be a matter of choice and should never be mandatory.

“We would be against any plans to make vaccination mandatory for certain activities or events for this age group – or indeed any under-18 year olds.

“Children, young people and all of society will directly benefit from an increase in vaccination uptake in the adult population, particularly by those in their 20s, 30s and 40s.  Tackling this pandemic, which is still ongoing, does not depend on vaccinating children, who have already borne a great deal on behalf of us all.”



All our previous output on this subject can be seen at this weblink:


Declared interests

Dr Simon Clarke: “No conflicts of interest” 

Dr Michael Head: “No declarations or conflicts of interest.”

Dr Julian Tang: “None.”

Prof Russell Viner: “No conflicts of interest.”

None others received.

in this section

filter RoundUps by year

search by tag