Inclusion Criteria: Children or young people< 18 years who are admitted to PCCU and who have an acute illness are eligible for participation in the study.  Children and young people from age 0 day to <18 years with confirmed COVID-19 illness and/or those who meet the Multisystem inflammatory syndrome case definition.  -  Exclusion Criteria:  Admitted to hospital for social reasons Or Declined consent by Parents or carers with legal responsibility or competent child Or Admitted to PCCU following a planned surgical procedure without an acute illness Or Direct clinical care team not able to provide research information in a language appropriate for non-English/Welsh speaking participants