High levels of antibodies 6 months after COVID‐19 vaccination in children with severe chronic diseases: A prospective longitudinal case series. (2nd February 2023) - Nygaard, Ulrikka; Kirkby, Nikolai Søren; Dungu, Kia Hee Schultz; Nielsen, Kim G.; Masmas, Tania; Juul, Klaus; Born, Peter; Buus, Søren; Stensballe, Lone Graff