AB1333 THE IMPACT OF IMMUNOCOMPROMISE ON OUTCOMES OF COVID-19 IN CHILDREN AND YOUNG PEOPLE - A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

BackgroundDespite children and young people (CYP) having a low risk for severe Coronavirus disease 2019 (COVID-19) outcomes, there is still a degree of uncertainty related to their risk in the context of immunodeficiency or immunosuppression, primarily due to significant reporting bias in most studies, as CYP characteristically experience milder or asymptomatic COVID-19 infection and the severe outcomes tend to be overestimated.ObjectivesTo systematically evaluate the impact of immunosuppression on severe COVID-19 infection outcomes in CYP and perform a meta-analysis to estimate differences in outcomes compared to general population.MethodsA comprehensive systematic review to identify globally relevant studies in immunosuppressed CYP and CYP in general population (defined as younger than 25 years of age) up to 31st October 2021 (to exclude vaccinated populations), was performed. Studies were included if they reported the two primary outcomes of our study, admission to intensive therapy unit (ITU) and mortality, while data on other outcomes, such as hospitalisation and need for mechanical ventilation were also collected. A meta-analysis estimated the pooled proportion for each severe COVID-19 outcome, using the inverse variance method. Random effects models were used to account for interstudy heterogeneity.ResultsThe systematic review identified 30 eligible studies for each of the two populations investigated: immunosuppressed CYP (n=793) and CYP in general population (n=102,022). Our meta-analysis found higher estimated prevalence for hospitalization (46% vs. 16%), ITU admission (12% vs. 2%), mechanical ventilation (8% vs. 1%) and increased mortality due to severe COVID-19 infection (6.5% vs. 0.2%) in immunocompromised CYP compared to CYP in general population (Figure 1A-D depicts the pooled estimates for the above outcomes in immunocompromised CYP). This analysis shows an overall trend for more severe outcomes of COVID-19 infection in immunocompromised CYP, similar to adult studies.ConclusionThis is the only up to date meta-analysis in immunocompromised CYP with high global relevance, which excluded reports from hospitalised cohorts alone and included 35% studies from low- and medium-income countries. Future research is required to characterise individual subgroups of immunocompromised patients, as well as impact of vaccination on severe COVID-19 outcomes.AcknowledgementsSpecial thanks to Prof. Lucy Wedderburn, Professor of Pediatric Rheumatology at University College London Institute of Child Health for providing useful comments.Disclosure of InterestsCoziana Ciurtin Speakers bureau: UCB, Grant/research support from: GSK, James Greenan- Barett: None declared, Samuel Aston: None declared, Claire Deakin: None declared.