An assessment of the vaccination of school-aged children in England against SARS-CoV-2

Abstract

Background Children and young persons are known to have a high number of close interactions, often within the school environment, which can facilitate rapid spread of infection; yet for SARS-CoV-2, it is the elderly and vulnerable that suffer the greatest health burden. Vaccination, initially targeting the elderly and vulnerable before later expanding to the entire adult population, has been transformative in the control of SARS-CoV-2 in England. However, early concerns over adverse events and the lower risk associated with infection in younger individuals means that the expansion of the vaccine programme to those under 18 years of age needs to be rigorously and quantitatively assessed. Methods Here, using a bespoke mathematical model matched to case and hospital data for England, we consider the potential impact of vaccinating 12–17 and 5–11-year-olds. This analysis is reported from an early model (generated in June 2021) that formed part of the evidence base for the decisions in England, and a later model (from November 2021) that benefits from a richer understanding of vaccine efficacy, greater knowledge of the Delta variant wave and uses data on the rate of vaccine administration. For both models, we consider the population wide impact of childhood vaccination as well as the specific impact on the age groups targeted for vaccination. Results Projections from June suggested that an expansion of the vaccine programme to those 12–17 years old could generate substantial reductions in infection, hospital admission and deaths in the entire population, depending on population behaviour following the relaxation of control measures. The benefits within the 12–17-year-old cohort were less marked, saving between 660 and 1100 (95% PI (prediction interval) 280–2300) hospital admissions and between 22 and 38 (95% PI 9–91) deaths depending on assumed population behaviour. For the more recent model, the benefits within this age group are reduced, saving on average 630 (95% PI 300–1300) hospital admissions and 11 (95% PI 5–28) deaths for 80% vaccine uptake, while the benefits to the wider population represent a reduction of 8–10% in hospital admissions and deaths. The vaccination of 5–11-year-olds is projected to have a far smaller impact, in part due to the later roll-out of vaccines to this age group. Conclusions Vaccination of 12–170-year-olds and 5–11-year-olds is projected to generate a reduction in infection, hospital admission and deaths for both the age groups involved and the population in general. For any decision involving childhood vaccination, these benefits needs to be balanced against potential adverse events from the vaccine, the operational constraints on delivery and the potential for diverting resources from other public health campaigns.

A methodological framework for assessing the benefit of SARS-CoV-2 vaccination following previous infection: case study of five to eleven year olds

“…In essence, we illustrate that there is robust evidence for net benefit from continued vaccination of the five to 11 year old cohort, even after previous infection with SARS-CoV-2, where the scale of benefit depends most strongly on the future attack rate and the time since last infection. This extends the work of Keeling and Moore [36], showing that accounting for meaningful waning is possible (albeit in a very simple way) and in doing so, illustrates the importance of considering timing of vaccination (with reference to previous infection). In essence, the question that this framework exposes as being critical to an evidence-based policy is: at what point since previous infection would it be beneficial to add the immunity from the vaccine, given we know that both vaccine-related and infection-related immunity wane?…”

“…Keeling and Moore have also modelled impact of vaccination in five to 11 year olds in England [36]. Their most recent reported run of the model was in November 2021 (prior to Omicron), with the results informing the decision-making of the UK approval body, the Joint Committee for Vaccination and Immunisation (JCVI).…”

Comparison of the 2021 COVID-19 roadmap projections against public health data in England

“…Although the development of the Warwick SARS-CoV-2 transmission and COVID-19 disease model has been described elsewhere in extensive detail 5 , 7 , 12 , 51 , here we summarise the main salient components and the method of parameter inference.…”

Impact of SARS-CoV-2 vaccination of children ages 5–11 years on COVID-19 disease burden and resilience to new variants in the United States, November 2021–March 2022: a multi-model study

“… 11 Another modeling study assessed the impact of vaccination on school interventions but did not explore national- or state-level benefits. 12 A single-model study evaluated impacts of school-aged children vaccination in the U.K. 13 Several other modeling studies have considered vaccination effects in the global context. 14 , 15 …”