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expert reaction to study looking at the risks and benefits of offering two doses of COVID-19 vaccine to children aged 12-17

A study accepted for publication by Journal of the Royal Society of Medicine carries out a risk-benefit analysis for vaccinating adolescents against SARS-CoV-2 in England.


Dr Michael Absoud, Honorary Reader, Dept of Women & Children’s Health, King’s College London

“Gurdasani et al present an interesting attempt to quantify a risk-benefit analysis of two doses of Covid vaccination, to inform the debate on vaccinating all children (12-17 years of age).  The paper has a number of methodological limitations that limit its generalisability to inform wider policy. It is also out of line with the subsequent formulation and recommendations by the UK’s 4 nations who consulted with the royal colleges, directors of public health and experts in data and modelling. 

“The JCVI and then the CMOs main consideration for this period, was specifically regarding vaccinating healthy 12-15 year olds with one dose of the Pfizer vaccine. The JCVI had already recommended that children and young people aged 12 to 17 years with specific underlying health conditions, and children and young people who are aged 12 years and over who are household contacts of persons who are immunocompromised are offered two doses of the Pfizer vaccine. They had also recommended that all young people 16 to 17 years are offered one dose of vaccine, pending further safety data.

“The paper mainly fails to consider appropriate population numerators and denominators for healthy children, which was the main focus of policy analysis recommendations.  Using case rates which vary depending on testing frequency leads to over-estimation of rates of hospitalisations, and inflate the benefit of vaccination. Infection based rates (available from sero-prevalence studies in schools and also ONS studies in 16 and 17 year olds) provide a more reliable indicator.”


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

“There are some important limitations to this analysis which make it of limited use given the current vaccination policy in the UK. Most importantly, it does not attempt to qualify the difference between a single dose of vaccination compared to 2 doses. This is current UK policy, and was made on the basis that a single dose offers the vast majority of the benefit of reductions of risk of hospitalisation and death, and avoids the worst of the potential adverse events of myocarditis, especially in young males. Without being able to offer a comparison of one vs two doses (which was presented in the JCVI analysis), this does not add to the current discussion.

“There are a number of other assumptions which make the conclusions questionable. Firstly, this analysis does not compare the difference between the risk to children with comorbidities and those who are otherwise healthy. Children with comorbidities making them at high risk of severe disease are already offered 2 doses. This removes the majority of the population wide benefit from mass immunisation, and there should have been an attempt made to account for this (as was done in the JCVI analysis).

“The authors incorrectly state that SAGE analysis reported 80% of admissions with a positive test were “for covid”. As an author of this analysis, this is a not a correct interpretation. As mentioned in the report, due to the method of ISARIC reported we can be fairly certain this is a overestimate, as many children admitted with incidental positive tests would not be reported. A recent cases series from London found 1 in 3 admissions to be incidental(1), and a case series from California found 40% to be incidental(2). Without correcting for this in the analysis, it will significantly overestimate reductions in hospitalisations.

“The discussion does not mention one of the primary concerns regarding immunisation, which is the lack of current long term follow up of cases of vaccine associated myocarditis. Whilst case reports of hospitalised cases are reassuring, not enough time has accrued for long term follow up to be available.

“At present in the UK, the JCVI concluded that the small individual benefit on balance likely outweighed the small risks of vaccination, but not by enough to recommend mass immunisation of healthy children. Children with comorbidities gain significantly more from vaccination. The CMOs were asked to consider wider societal benefits, and concluded that with the potential to reduce disruption to schooling, offering a single dose to otherwise healthy children was worthwhile. This is in line with current policy in Norway.

“Without accounting for the differences between a single and double dose strategy, or the differential in risk between children with comorbidities and otherwise healthy children, this analysis doesn’t seem to bring us further forward in the discussion.”

(1)          Brookman, Sarah et al. Effect of the new SARS-CoV-2 variant B.1.1.7 on children and young people, The Lancet Child & Adolescent Health, Volume 5, Issue 4, e9 – e10

(2)          Kushner LE, et al. “For COVID” or “With COVID”: Classification of SARS-CoV-2 Hospitalizations in Children. Hosp Pediatr. 2021; doi: 10.1542/hpeds.2021-006001


Prof Penny Ward, Independent Pharmaceutical Physician, Visiting Professor in Pharmaceutical Medicine at King’s College London, said:

“This publication provides timely, relevant input for parents and children aged 12-17 currently considering whether or not to accept covid vaccination. The authors have used data from England to calculate the infections, hospitalisations, ICU admissions and deaths from COVID which would be prevented by complete vaccination of children 12 and over. Even at an incidence 10 fold lower than teenagers are currently experiencing, the benefits of vaccination far exceed the known risks of vaccines in this age group.

“The information should be very reassuring to parents and their children struggling to decide what to do in the face of conflicting advice from different quarters. In addition to considering impact on acute covid illness, the authors have extended their assessment to consider impact of preventing covid on potential for long covid – an illness which is currently poorly understood but which might cause significant long term morbidity in the young. Here too the benefit of vaccination far exceeds its risks.

“This analysis would be benefited further if the authors extended their analysis to consider the impact of the first dose of vaccine, given that most otherwise healthy children will initially be offered a first dose while discussion on the timing of a second dose continues. This additional assessment could be very helpful to JCVI and others still considering the final vaccination schedule in this age group.”



‘Vaccinating adolescents against SARS-CoV-2 in England: a risk-benefit analysis’ by Deepti Gurdasani et al has been accepted for publication by the Journal of the Royal Society of Medicine and a copy will be publicly shared at 00:05 UK time on Thursday 30th September 2021.



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



Declared interests

None received.

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