Table 1

Arguments for and against vaccinating children against COVID-19

Arguments for COVID-19 vaccinationArguments against COVID-19 vaccination
Benefits of vaccinating children
(1) Protection against COVID-19
  • Good justification if risk of SARS-CoV-2 infection is high

  • Risk of harm from vaccination lower than risk of harm from COVID-1991

  • Clear benefit for children with risk factors for severe COVID-1941

  • Risk of hospitalisation and death from COVID-19 is commensurate with or higher than other diseases in routine immunisation programme42

  • Higher disease burden of COVID-19 in children in LMICs with comorbidities that impact immunity33

  • Higher immunogenicity of mRNA vaccines in children might mean one or lower dose sufficient25

  • Adolescents have a higher frequency of infection and disease burden than younger children

  • Children are less likely to get infected after a SARS-CoV-2 exposure77 111–114

  • Most children have asymptomatic or mild COVID-191–8

  • A large proportion of children might already be immune to SARS-CoV-2 in many regions of the world

  • Risk of COVID-19 in children might be less if large proportion of adult population is vaccinated

(2) Protection against severe COVID-19
  • Risk of severe COVID-19 in children with underlying diseases is not negligible1–8

  • Risk of severe COVID-19 in healthy children might be higher with SARS-CoV-2 current or future variants of concern

  • Risk of severe COVID-19 in healthy children is low1–8

  • At-risk children could be protected by targeted rather than universal vaccination

(3) Protection against PIMS-TS
  • No long-term data on children with PIMS-TS; if sequelae are important, the risk–benefit of COVID-19 vaccination might change

  • No data yet on whether vaccination prevents PIMS-TS

  • Risk of PIMS-TS is low, and children mainly recover without sequelae11–19

  • COVID-19 vaccination might increase risk of PIMS-TS (no evidence to date)

(4) Protection against long COVID-19
  • Long COVID-19 can occur even after mild or asymptomatic infection55 57 58 61 65 66

  • Not well studied yet; could affect a large number of children

  • The incidence of long COVID-19 is still to be accurately determined21

  • Difficult to separate infection-associated from pandemic-associated symptoms55 61 65

(5) Prevention of community transmission
  • Children, even young children, can transmit SARS-CoV-2115

  • Prevention of transmission to other children and older age groups

  • Prevention of transmission to high-risk household members

  • Herd immunity likely inachievable without vaccinating children and adolescents

  • Reduction in the risk of new VOC emerging

  • Risk of transmission might be changing with emergence of new VOC (eg, Delta)

  • Potential considerable indirect benefit (eg, schools remaining open) to children even if no direct benefit (see (6))

  • ‘No one is safe until we are all safe’

  • No data yet on whether vaccination prevents transmission in children

  • Transmission in educational settings is rare and index cases are often adults78–81

  • Index cases in households much more likely to be a parent or adolescent6

  • Community transmission will decrease if sufficient adults are vaccinated69

  • Subjecting children to potential risk of vaccine adverse effects to drive indirect effects with little or no direct benefit might be ethically questionable

  • Effect of vaccination on transmission might decrease with waning immunity and emergence of VOC

  • Primary infection at young age when the disease is mild combined with boosting exposure from ongoing transmission at older age might be better strategy90

(6) Avoidance of indirect harms, including quarantine, school closure and other harms of lockdowns
  • Transmission in school can contribute to the circulation of SARS-CoV-277

  • Lockdowns and school closures have a major impact on physical and mental health of children116

  • Vaccinated children might be exempt from quarantine

  • COVID-19 vaccination might become a requirement for international travel

  • Might not be sufficient to prevent school closures and lockdowns (especially if a large proportion of adults are not vaccinated)

  • Might not be necessary to prevent school closures and lockdowns, especially if adult staff are all immunised

Risks of vaccinating children
(1) Risk of adverse effects
  • Myocarditis after mRNA vaccines is transient and usually without sequelae91

  • No reports of thrombosis after viral vector vaccines in children and adolescents to date99

  • No reports of PIMS-TS after vaccination to date

  • Myocarditis after mRNA vaccines including need for intensive care91–98 117

  • Potential risk of thrombosis after viral vector vaccines

  • Potential trigger for PIMS-TS (no evidence to date)

(2) Long-term safety
  • Adverse effects of vaccines usually occur early

  • Long-term safety in children, including following myocarditis, unknown

  • If concerns arise, this might lead to decrease in vaccine confidence and vaccine uptake, including against other diseases102

  • No studies to date have evaluated co-administration with other vaccines

(3) Vaccine supply
  • One dose or a reduced dose might be sufficient in children

  • Current limited vaccine supply should be prioritised for people at high risk of severe disease and death

  • Vaccine supply might be better used for adults in LMICs where <5% of population have been vaccinated103

(4) Cost
  • Greater herd immunity likely better for returning to pre-pandemic economic stability

  • Likely higher cost–benefit ratio in children

(5) Other immunisation programmes
  • Could be combined with the administration of other routine vaccines

  • Implementation of universal COVID-19 vaccination programme in children could cause delays in the routine immunisation programmes by using up existing delivery resources and personnel

  • LMICs, low/middle-income countries; mRNA, messenger RNA; PIMS-TS, paediatric inflammatory multisystem syndrome-temporally associated with SARS-CoV-2.