Vaccinating adolescents against SARS-CoV-2 in England: a risk-benefit analysis

Abstract

Objective: To offer a quantitative risk-benefit analysis of two doses of SARS-CoV-2 vaccination among adolescents in England.

Setting: England.

Design: Following the risk-benefit analysis methodology carried out by the US Centers for Disease Control, we calculated historical rates of hospital admission, Intensive Care Unit admission and death for ascertained SARS-CoV-2 cases in children aged 12-17 in England. We then used these rates alongside a range of estimates for incidence of long COVID, vaccine efficacy and vaccine-induced myocarditis, to estimate hospital and Intensive Care Unit admissions, deaths and cases of long COVID over a period of 16 weeks under assumptions of high and low case incidence.

Participants: All 12-17 year olds with a record of confirmed SARS-CoV-2 infection in England between 1 July 2020 and 31 March 2021 using national linked electronic health records, accessed through the British Heart Foundation Data Science Centre.

Main outcome measures: Hospitalisations, Intensive Care Unit admissions, deaths and cases of long COVID averted by vaccinating all 12-17 year olds in England over a 16-week period under different estimates of future case incidence.

Results: At high future case incidence of 1000/100,000 population/week over 16 weeks, vaccination could avert 4430 hospital admissions and 36 deaths over 16 weeks. At the low incidence of 50/100,000/week, vaccination could avert 70 hospital admissions and two deaths over 16 weeks. The benefit of vaccination in terms of hospitalisations in adolescents outweighs risks unless case rates are sustainably very low (below 30/100,000 teenagers/week). Benefit of vaccination exists at any case rate for the outcomes of death and long COVID, since neither have been associated with vaccination to date.

Conclusions: Given the current (as at 15 September 2021) high case rates (680/100,000 population/week in 10-19 year olds) in England, our findings support vaccination of adolescents against SARS-CoV2.

Keywords: Clinical; evidence-based practice; non-clinical; paediatrics; public health; vaccination programmes.

Figure 1.

Time series of daily hospital admissions (seven-day running average) with COVID-19 among 6–17 year olds from 1 April 2020 to 13 September 2021. Data downloaded from https://api.coronavirus.data.gov.uk/v2/data?areaType=nation&areaCode=E92000001&metric=cumAdmissionsByAge&format=csv.

Figure 2.

Risk–benefit of COVID-19 vaccination in adolescents at high and low incidence levels. (a and b) A comparison of specific outcomes among adolescents aged 12–17 years of age calculated over a 16-week period assuming different levels of exposure with high incidence of 1000 per 100,000 per week (reflecting the current case rates in this age group in England) and low incidence of 50 per 100,000 per week, corresponding to end of April 2021. Note: the scales for (a) and (b) are different for ease of visualisation. In all cases, direct benefits of vaccination appear to considerably outweigh risks. Values above 50 have been rounded to the closest 10. Myocarditis here refers to both vaccine-related myocarditis and pericarditis. We show long COVID estimates assuming an incidence rate of 4% – see results section for equivalent estimates of 2% and 14% incidence. *Note: Total hospitalised considers hospitalisations from COVID-19 and vaccine-related myocarditis/pericarditis (assuming a worst-case scenario that all cases of myocarditis are hospitalised).

Figure 3.

Hospitalisations* and deaths averted by COVID-19 vaccination in adolescents at different incidence levels. (a and b) The number of hospitalisations,* and deaths averted as a function of case incidence among 12–17 year olds over a 16-week period. For hospitalisations, we represent these separately for boys and girls to account for the differing rate of vaccine-related myocarditis. Myocarditis here refers to both vaccine related myocarditis and pericarditis. *Note: Total hospitalised considers hospitalisations from COVID-19 and vaccine-related myocarditis/pericarditis (assuming a worst-case scenario that all cases of myocarditis are hospitalised).