Association of the rs2814778 variant in the ACKR1 gene, responsible for the Duffy erythrocyte antigen "null" phenotype, with COVID-19 severity in Southern Brazil. - Góis KS; Braga M; Souza VH; Schavaren J; Grava S; Simão ANC; Visentainer JEL; Lima Neto QA (Einstein (Sao Paulo, Brazil), 2026)