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

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