Children in Hong Kong between the ages of 12-17 can be vaccinated with either BioNTech or Sinovac vaccine. The government has announced vaccinations for children between 5-11 years with both BioNTech and Sinovac vaccines. BioNTech will be given as one-third of the adult dose whilst approval for the paediatric version is pending. Is there evidence to support this decision?
The main issues in the vaccination of children are covered in the following questions.
Is COVID-19 generally a mild disease in Childhood?
A study in the Lancet reviewing data from seven countries showed an estimated 2 in every million deaths in children. The majority occurring in those with other medical conditions and risk factors. Clearly, any death in childhood is a tragedy but when risks of the disease are so low, we would normally need overwhelming evidence of safety before recommending widespread vaccination.
Are COVID-19 vaccinations in children safe?
We have evidence of both the effectiveness and safety of COVID-19 vaccinations in children from multiple populations.
Are there side effects of COVID-19 vaccinations?
The main side effect of the BioNTech vaccine is myocarditis (inflammation of the heart). A recent study suggested that COVID-19 vaccination may cause more hospitalisations than it prevents in adolescent boys. The condition resolves naturally in the vast majority of cases without treatment. The rates of hospitalised cardiac adverse events (mainly myocarditis) in boys following the second BioNTech dose were 162 per million (ages 12 - 15) and 94 per million (ages 16 - 17); among females, rates were 13.0 and 13.4 per million, respectively. Hong Kong initially advised giving only a single shot to children age 12 to 17 years to reduce this risk, although children are now entitled to a booster shot at least 3 months after the first injection. It has been reported that myocarditis is rare in children less than 12 years of age.
Sinovac has been given to children and adolescents in China and other countries with no reported increase in side effects. However, Sinovac contains Aluminium Hydroxide as an adjuvant and as yet there has been no large peer-reviewed trials of safety in children.
Is mortality the only measure of disease severity?
Clearly there is more to disease severity than mortality. Indeed, there is an argument that in young people and children the greatest indication for vaccination may be the prevention of Long Covid. We are accumulating evidence that vaccination reduces the risks of Long Covid by up to 90%. We know that Long Covid can affect children and the impact can be significant.
In addition to Long Covid we must also consider the impact on a child’s education and social development. In Hong Kong schools are limited in teaching face to face dependent on vaccination rates. The increasing use of vaccine passes and the application of quarantine regulations also has the potential to adversely impact normal family life.
Will vaccinating children allow us to reach herd immunity?
We have explained in a previous article that the delta variant makes herd immunity impossible by vaccination alone. Omicron will make this even harder. It will certainly be much harder if we do not vaccinate children, but this raises an ethical question. Is it ethical to vaccinate a child predominantly to protect the elderly and vulnerable rather than the child? I would argue not and especially when the elderly and vulnerable are refusing to be vaccinated. We should only vaccinate children if there is clear evidence of risk-benefit in favour of the child.
If I only have one dose of the vaccine who will benefit the most?
Answer: The elderly, vulnerable and those in high-risk occupations
An elderly and vulnerable person is many hundreds of times more likely to die of Covid than a child or adolescent. The elderly are also more likely to end up in hospital and intensive care which can overload the health system. The risk to a child in Hong Kong, from an overloaded health system preventing treatment of another condition, is significantly greater than their risk from Covid.
Taking a reductionist and utilitarian perspective we should be vaccinating the most vulnerable rather than vaccinating children.
Do we really have a vaccine shortage?
The counter-argument is that supplies and logistics is not a justification to risk the lives or health of children. There are many vaccines available in Hong Kong. We should offer them to everybody who would like to take one.
So should we be vaccinating children?
Public health decisions are ultimately a balance of individual versus population risk/benefit and are frequently nuanced. In the UK the Joint Committee on Vaccination and Immunization voted against vaccination for children but the Chief Medical Officers disagreed and advised vaccination for children over 12 years of age. The general trend internationally is towards vaccination of older children and this is likely to continue as safety data accumulates. Vaccination of younger children is a more balanced decision.
Serious illness (A) is fortunately very rare in young children (not zero).
Serious side effects of vaccinations (B) are fortunately very rare in young children (not zero).
We would normally require very good evidence that A is greater than B before undertaking a mass vaccination program for young children.
The evidence for vaccinating children is less clear than the evidence for the elderly and the evidence for young children less clear than for older children. Ultimately it must be an individual choice to be made by parents. In Hong Kong, we have doubled down on a zero Covid strategy*. This also changes the risk-benefit analysis. At some point, if the risk of the disease is so small then even tiny risks of vaccination may exceed the benefit. There is certainly an argument, in this context, to delay vaccination in children until the strategy changes and the risk-benefit shifts in favour of widespread vaccination. This may happen if we begin to see widespread infections in the community.
Addendum for February 2022
*The original article was written in September 2021, in the context of a zero Covid public health strategy. In Hong Kong, we are now seeing widespread infections in the community. This is likely to continue over the next three months. Notwithstanding government communications suggesting a return to zero, the risk of Covid in Hong Kong over the next three months is likely to be significantly higher than the risk in the rest of the world over the subsequent six months. We have increasing evidence of safety in larger numbers of children. The UK is soon to start vaccinating 5 to 11-year-olds. In this context, it remains my opinion that vaccinating children should be a parental choice but the risk-benefit has shifted towards vaccinating children.
1. R;, B. S. S. B. J. O. B. B. (n.d.). Children and young people remain at low risk of COVID-19 Morality. The Lancet. Child & Adolescent Health. Retrieved September 16, 2021, from https://pubmed.ncbi.nlm.nih.gov/33713603/.
2. Høeg, T. B., Krug, A., Stevenson, J., & Mandrola, J. (2021, January 1). Sars-CoV-2 mRNA vaccination-associated myocarditis in children ages 12-17: A stratified national database analysis. medRxiv. Retrieved September 16, 2021, from https://www.medrxiv.org/content/10.1101/2021.08.30.21262866v1.
3. Scientific Committee on Emerging and Zoonotic Diseases and Scientific Committee on Vaccine Preventable Diseases. Centre for Health Protection. (2021, September 15). Retrieved September 16, 2021, from https://www.chp.gov.hk/files/pdf/consensus_interim_recommendations_on_the_use_of_covid19_vaccines_in_hk_15sept21.pdf.
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5. Öcal Demir et al. (2021). ‘SARS-CoV-2 associated multisystem inflammatory syndrome in children (MIS-C). A single center's experience’. Minerva Pediatrics. 23 April 2021. Available at: <https://pesquisa.bvsalud.org/global-literature-on-novel-coronavirus-2019-ncov/resource/pt/covidwho-1200473> [Accessed 10 September 2021].
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