At present the Joint Committee on Vaccination and Immunisations (JVCI) has recommended that healthy 12- to 17-year-olds only receive one dose of the vaccine, pending further evidence on effectiveness. However, young people who are also in at-risk groups or household contacts of an immunosuppressed person should receive two doses, the JCVI has said.
This latest study, published in the Journal of the Royal Society of Medicine, looked at the direct benefit to children from receiving two doses of the vaccination.
It did not consider secondary benefits such as onwards transmission or education disruption. These were considerations that the UK's CMOs took into account when they recommended that 12- to 15-year-olds should be vaccinated after the JCVI concluded the benefits of vaccination only 'marginally outweighed' the risks.
The researchers estimated COVID-19-related hospital and ICU admissions, deaths and cases of long COVID that would be averted over a 16-week period by vaccinating all 12- to 17-year-olds in England. The estimates were based on data across all of these factors in children aged 12-17 in England from 1 July 2020 to 31 March 2021 and PHE data on case rates during this period.
The researchers also looked at data from the US Center for Disease Control on estimates of vaccine associated myocarditis/pericarditis following the first and second doses of vaccine.
They assumed that all 12- to 17-year-olds in England were vaccinated and used 'conservative' estimates of vaccine effectiveness in reducing severe outcomes and infections after two doses. This meant calculations were based on two doses of the vaccine reducing severe outcomes in cases of the Delta variant by 90% and reducing the risk of infection by 64%.
As at 15 September 2021 case rates among 10- to 19-year-olds were 680 cases per 100,000 population per week.
The researchers estimated that if cases rose to 1,000 per 100,000 population per week, vaccinating teenagers would avert 4,430 hospital admissions and 36 deaths over a 16-week period.
Even at a rate of 50 cases per 100,000 population per week, vaccinating this cohort would avoid 70 hospital admissions and two deaths over a 16-week period, the researchers said.
The study also suggested that at the higher case rate level, vaccination would avert around 56,000, 16,000, or 8,000 cases of long COVID in 12- to 17-year-olds, assuming the proportion of teenagers with COVID-19 going on to develop long COVID is 14%, 4%, and 2% respectively.
The researchers found that the risk of hospitalisation because of vaccination only exceeded the risk of hospitalisation with COVID-19 when cases fell below 30 per 100,000 population per week. They noted that COVID-19 rates in adolescents in England had not been this low during any week in 2021.
However they added: '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.'
The researchers concluded that 'on clinical risks alone, vaccination is warranted for 12- to 17-year-olds'. They added: 'Considering secondary impacts of vaccination (e.g. on transmission or educational disruption) would further tip the balance towards vaccination.'
Lead author, Dr Deepti Gurdasani, from Queen Mary University of London, said: 'This analysis shows that, on clinical risks alone, vaccination is warranted for 12- to 17-year-olds in England. While we wait to understand the long-term effects of COVID-19 on children, the precautionary principle advocates for protecting all children from exposure to this virus and vaccination is a crucial part of that protection.'
She added: 'While children with pre-existing illnesses may be at greater individual risk, 60% of hospitalisations in under 18s in England have been amongst children who do not have such conditions, suggesting considerable benefits for all children in reducing severe illness through vaccination.'
Professor Martin McKee, of the London School of Hygiene & Tropical Medicine and another of the researchers contributing to the study, said: 'The approach taken by the JCVI is completely out of line with that of advisors in many other countries so it really should explain why it thinks they are wrong.'